Alguém me ajuda nessas questões pfv
Anexos:
Usuário anônimo:
ok, então faço a 12
12, ok!
aiiii muito obg Paulo, sério msm
vc encontrou dois anjos... rs
Soluções para a tarefa
Respondido por
1
12.
a)
a = 2
a + 6 5
5a = 2(a + 6)
5a = 2a + 12
5a - 2a = 12
3a = 12
a = 12/3
a = 4
*************************************************
b)
1 + 2 = 3
x - 3 x - 3
1 + 2(x - 3) = 3
x - 3 x - 3
1 + 2x - 6 = 3
- 5 + 2x = 3
2x = 3 + 5
2x = 8
x = 8/2
x = 4
******************************************
c)
4 - 6 = - 2 - 5x
x + 2 x - 2 (x² - 4)
4.(x - 2) - 6.(x + 2) = - 2 - 5x
(x + 2).(x - 2) (x + 2).(x - 2)
4(x - 2) - 6.(x + 2) = - 2 - 5x
(x + 2).(x - 2) (x + 2).(x - 2)
4x - 8 - 6x - 12 = - 2 - 5x
- 2x - 20 = - 2 - 5x
- 2x + 5x = - 2 + 20
3x = 18
x = 18/3
x = 6
***************************
d)
3 - x + 2 = - 11
2 3x 6x
mmc (2,3x, 6x) = 6x
3.3 - 2(x + 2) = - 11
6x 6x
9 - 2x - 4 = - 11
5 - 2x = - 11
- 2x = - 11 - 5
- 2x = - 16 ( - 1)
2x = 16
x = 16/2
x = 8
**************************************
e)
4 + 3x = 3
x x - 2
mmc (x, x - 2) = x(x - 2)
4.(x - 2) + 3x.x = 3x(x - 2)
x.(x - 2) x.(x - 2)
4x - 8 + 3x² = 3x² - 6x
4x - 8 = - 6x
4x + 6x = 8
10x = 8 (:2)
5x = 4
x = 4/5
***********************************
f)
5 - 2 = x
x - 3 x + 3 x² - 9
mmc = (x - 3).(x + 3)
5.(x + 3) - 2.(x - 3) = x
(x - 3).(x + 3) (x - 3).(x + 3)
5x + 15 - 2x + 6 = x
3x + 21 = x
3x - x = - 21
2x = - 21
x = - 21/2
***************************************
g)
2x - 8 = 3x - 3x
x² - 25 x + 5 x - 5
mmc = (x + 5).(x - 5)
2x - 8 = 3x.(x- 5) - 3x.(x + 5)
(x + 5).(x - 5) (x + 5).(x - 5)
2x - 8 = 3x² - 15x - 3x² - 15x
2x - 8 = - 30x
2x + 30x = 8
32x = 8 (:8)
4x = 1
x = 1/4
**********************************************
h)
3 - 4 = 1
x 5x 10
mmc = (x,5x,10) = 50x
50.3 - 4.10 = 5x
150 - 40 = 5x
110 = 5x
5x = 110
x = 1105
x = 22
******************************************************
Prova real:
3 - 4 = 1
22 5.22 10
3 - 4 = 5.3 - 4 = 15 - 4 = 11 (:11) = 1
22 110 110 110 110 (:11) 10
-----------------------------------------------
*************************************
13.
a)
2x + 3 + x + 1 = 3x+ 4 = 3x + 4
x.(x + 1) x(x + 1) x² + x
x(x + 1) = x² + x
mmc = x(x + 1)
*****************************************************
b)
4.3a - 5a + 2.7a = 12a - 5a + 14a = 21a
4x 4x 4x
mmc = 4x
---------------------------------------------------
c)
3 - 2 = 3(x + 1) - 2x = 3x + 3 - 2x = x + 3
x x + 1 x.(x + 1) x + 1 x + 1
--------------------------------------------------------------------------------------
d)
a + b + 2a + b - 3a + b = a + 2a - 3a + b + b + b =>
a²b a²b a²b a²b
= 3a - 3a + 3b
a²b
= 3b = 3
a²b a²
*************************************************
e)
a + 2b - a - 2b - 4bx - 2a²
x + a x - a (x + a).(x - a)
(x - a).(a - 2b) - (x + a).(a - 2b) - 4bx - 2a²
(x + a).(x - a)
ax - 2bx - a² + 2ab - (ax - 2bx + a² - 2ab) - 4bx - 2a²
(x + a).(x - a)
ax - 2bx - a² + 2ab - ax + 2bx - a² + 2ab - 4bx - 2a²
(x + a).(x - a)
(ax - ax - 2bx + 2bx = 0)
= - a² - a² - 2a² + 2ab + 2ab - 4bx
(x + a).(x - a)
= - 2a² + 4ab - 4bx - 2a²
(x + a).(x - a)
= - 4a² - 4bx + 4ab
x² - a²
a)
a = 2
a + 6 5
5a = 2(a + 6)
5a = 2a + 12
5a - 2a = 12
3a = 12
a = 12/3
a = 4
*************************************************
b)
1 + 2 = 3
x - 3 x - 3
1 + 2(x - 3) = 3
x - 3 x - 3
1 + 2x - 6 = 3
- 5 + 2x = 3
2x = 3 + 5
2x = 8
x = 8/2
x = 4
******************************************
c)
4 - 6 = - 2 - 5x
x + 2 x - 2 (x² - 4)
4.(x - 2) - 6.(x + 2) = - 2 - 5x
(x + 2).(x - 2) (x + 2).(x - 2)
4(x - 2) - 6.(x + 2) = - 2 - 5x
(x + 2).(x - 2) (x + 2).(x - 2)
4x - 8 - 6x - 12 = - 2 - 5x
- 2x - 20 = - 2 - 5x
- 2x + 5x = - 2 + 20
3x = 18
x = 18/3
x = 6
***************************
d)
3 - x + 2 = - 11
2 3x 6x
mmc (2,3x, 6x) = 6x
3.3 - 2(x + 2) = - 11
6x 6x
9 - 2x - 4 = - 11
5 - 2x = - 11
- 2x = - 11 - 5
- 2x = - 16 ( - 1)
2x = 16
x = 16/2
x = 8
**************************************
e)
4 + 3x = 3
x x - 2
mmc (x, x - 2) = x(x - 2)
4.(x - 2) + 3x.x = 3x(x - 2)
x.(x - 2) x.(x - 2)
4x - 8 + 3x² = 3x² - 6x
4x - 8 = - 6x
4x + 6x = 8
10x = 8 (:2)
5x = 4
x = 4/5
***********************************
f)
5 - 2 = x
x - 3 x + 3 x² - 9
mmc = (x - 3).(x + 3)
5.(x + 3) - 2.(x - 3) = x
(x - 3).(x + 3) (x - 3).(x + 3)
5x + 15 - 2x + 6 = x
3x + 21 = x
3x - x = - 21
2x = - 21
x = - 21/2
***************************************
g)
2x - 8 = 3x - 3x
x² - 25 x + 5 x - 5
mmc = (x + 5).(x - 5)
2x - 8 = 3x.(x- 5) - 3x.(x + 5)
(x + 5).(x - 5) (x + 5).(x - 5)
2x - 8 = 3x² - 15x - 3x² - 15x
2x - 8 = - 30x
2x + 30x = 8
32x = 8 (:8)
4x = 1
x = 1/4
**********************************************
h)
3 - 4 = 1
x 5x 10
mmc = (x,5x,10) = 50x
50.3 - 4.10 = 5x
150 - 40 = 5x
110 = 5x
5x = 110
x = 1105
x = 22
******************************************************
Prova real:
3 - 4 = 1
22 5.22 10
3 - 4 = 5.3 - 4 = 15 - 4 = 11 (:11) = 1
22 110 110 110 110 (:11) 10
-----------------------------------------------
*************************************
13.
a)
2x + 3 + x + 1 = 3x+ 4 = 3x + 4
x.(x + 1) x(x + 1) x² + x
x(x + 1) = x² + x
mmc = x(x + 1)
*****************************************************
b)
4.3a - 5a + 2.7a = 12a - 5a + 14a = 21a
4x 4x 4x
mmc = 4x
---------------------------------------------------
c)
3 - 2 = 3(x + 1) - 2x = 3x + 3 - 2x = x + 3
x x + 1 x.(x + 1) x + 1 x + 1
--------------------------------------------------------------------------------------
d)
a + b + 2a + b - 3a + b = a + 2a - 3a + b + b + b =>
a²b a²b a²b a²b
= 3a - 3a + 3b
a²b
= 3b = 3
a²b a²
*************************************************
e)
a + 2b - a - 2b - 4bx - 2a²
x + a x - a (x + a).(x - a)
(x - a).(a - 2b) - (x + a).(a - 2b) - 4bx - 2a²
(x + a).(x - a)
ax - 2bx - a² + 2ab - (ax - 2bx + a² - 2ab) - 4bx - 2a²
(x + a).(x - a)
ax - 2bx - a² + 2ab - ax + 2bx - a² + 2ab - 4bx - 2a²
(x + a).(x - a)
(ax - ax - 2bx + 2bx = 0)
= - a² - a² - 2a² + 2ab + 2ab - 4bx
(x + a).(x - a)
= - 2a² + 4ab - 4bx - 2a²
(x + a).(x - a)
= - 4a² - 4bx + 4ab
x² - a²
todas feitas
Brigadão
vc é o melhor
ah resposta é 0 ?
Respondido por
0
12) (g)
2x - 8 3x 3x
-------- = ------- - -------- mmc = (x + 5)(x - 5)
x² - 25 x + 5 x - 5
1(2x - 8) = 3x(x - 5) - 3x(x + 5) fração com igual
-----------------------------------------despreza o denominador
(x+5)(x -5)
1(2x - 8) = 3x(x - 5) - 3x(x + 5)
2x - 8 = 3x² - 15x - 3x² - 15x
2x - 8 = 3x² - 3x² - 15x - 15x
2x - 8 = 0 - 30x
2x + 30x = + 8
32x = 8
x = 8/32 (divide AMBOS por 8)
x = 1/4
12)(h)
3 4 1
--- - ----- = ----- (mmc) = (x)(5x)(10)
x 5x 10
3((5x)(10)) - 4((x)(10)) = 1((x)(5x))
---------------------------------------------- idem acima
(x)(5x)(10)
3((5x)(10)) - 4((x)(10)) = 1((x)(5x))
3(50x) - 4(10x) = 1(5x²)
150x - 40x = 5x²
110x = 5x²
5x² = 110x
5x² - 110x = 0
5x(x - 22) = 0
5x = 0
x = 0/5
x = 0
e
(x - 22) = 0
x - 22 = 0
x = + 22
x'= 0
x" = 22
questão (13)
a)
2 3 1
------------- + ---------- + ----------- mmc= (x + 1)(x² + x)(x)
(x+1) (x² + x) (x)
2((x² +x)(x)) + 3((x+1)(x)) + 1((x²+x)(x+1))
---------------------------------------------------
(x+1)(x² + x)(x)
2(x³ + x²) + 3(x² + 1x) + 1(x³ + 1x² + x² + 1x)
----------------------------------------------------------
(x+1)(x² +x)(x)
2x³ + 2x² + 3x² + 3x + 1x³ + 1x² + 1x² + 1x
----------------------------------------------------------(JUNTA termos iguais)
(x+1)(x² + x)(x)
2x³ + 1x³ +2x² + 3x² + 1x² + 1x² +3x + 1x
-----------------------------------------------------
(x+1)(x³ + x²)
3x³ + 7x² + 4x
---------------------
(x⁴ + x³ + x³ + x²)
3x³ + 7x² + 4x
-------------------
(x⁴ + 2x³ + x²)
x(3x² + 7x + 4) : x (3x² + 7x + 4)
----------------------- = -----------------------
x(x³ + 2x² + x) : x (x³ + 2x² + x)
13(b)
3a 5a 7a
---- - ---- + -----
x 4x 2x (mmc)=(x)(4x)(2x)
3a((4x)(2x)) - 5a((x)(2x)) + 7a((x)(4x))
-----------------------------------------------------
(x)(4x)(2x)
3a(8x²) - 5a(2x²) + 7a(4x²)
--------------------------------------
(4x)(2x²)
24ax² - 10ax² + 28ax²
-------------------------------
(4x)(2x²)
2ax²(12 - 5 + 14) : (2x²) a(12+14 -5) a(26 - 5) a(21)
------------------------------- = -------------------- = ------------- = ------------
(4x)(2x²) : ( 2x²) 4x 4x 4x
13(c)
3 2
--- - ----------- (mmc) = (x)(x+1)
x x + 1
3(x +1) - 2(x)
-----------------------
(x)(x+1)
3x + 3 - 2x 3x - 2x + 3 1x + 3 x + 3
---------------- = --------------- = ------------- = --------
(x)(x +1) x² + 1x x² + 1x x ² + x
13(d)
a + b 2a + b 3a + b
------- + --------- - ------------
a²b a²b a²b
1(a + b) +1( 2a+b) -1( 3a + b)
---------------------------------------
a²b
a + b + 2a + b - 3a - b
-------------------------------
a²b
a +2a - 3a + b + b - b
----------------------------
a²b
3a - 3a + 2b - b
---------------------
a²b
0 + 1b
-----------
a²b
1b 1b : b 1
---- = --------- = -------------
a²b a²b : b a²
13 (e)
a +2b a - 2b 4bx - 2a²
-------- - ----------- - --------------- (mmc) = (x+a)(x -a)
x+a x - a x² - a²
((x -a)(a+2b)) - ((x +a)(a -2b)) - 1(4bx - 2a²)
------------------------------------------------------------
(x +a)(x -a)
(ax +2bx -a² -2ab) - (ax - 2bx +a² - 2ab) - (4bx - 2a²)
-----------------------------------------------------------------------
(x+a)(x -a)
ax + 2bx - a² - 2ab - ax + 2bx - a² + 2ab - 4bx + 2a²
-------------------------------------------------------------------
(x + a)(x - a)
-a² - a² + 2a² -ax - ax + 2bx + 2bx - 4bx - 2ab + 2ab
-------------------------------------------------------------------
( x + a)(x - a)
0 - 2ax 0 0
- 2ax
------------------
(x + a)(x - a)
- 2ax 2ax
----------- = - -------------
x² - a² x² - a²
obrigadaaa vc ajudou muitooo msm
Perguntas interessantes