Question

1.Resolver as seguintes equações do 1º grau:

a)5x – 40 = 2 – x


B)20 + 6x = -2x + 28


C)3,5x + 1 = 3 + 3,1x


D)9t – 14 = 7t + 20

E)5 – a – 11 = 4a – 21


F)2y + 21 – 6y = - 12 + y – 7

G)3(x – 2) – (1 – x) = 13


H)6(4 – t) – 55 = - 5(2t+ 3)

i) 5 – 4(x – 1) = 4x – 3(4x – 1) – 4

Answer 1

Resposta:

a) x= 7

b) x=1

c)x=1,6

d)t=17

e)a=7,2

f)y=8

g)x=5

h)t=16

I)x=4

Explicação passo-a-passo:

a)5x – 40 = 2 – x

5x +x= 2 +40

6x= 42

x=42/6

x=7

B)20 + 6x = -2x + 28

6x +2x = 28 -20

8x= 8

x= 8/8

x=1

C)3,5x + 1 = 3 + 3,1x

3,5x -3,1x = 3 -1

0,4x = 2

x= 2 -0,4

x= 1,6

D)9t – 14 = 7t + 20

9t -7t = 20 +14

2t = 34

t= 34 /2

t=17

E)5 – a – 11 = 4a – 21

-a -4a = -21 -11 -5

-5a = -31 -5

-5a= -36

a= -36 /-5

a= 7,2

F)2y + 21 – 6y = - 12 + y – 7

2y -6y -y = -12 -7 -21

-4y -y = -19 -21

-5y = -40

y= -40 /-5

y=8

G)3(x – 2) – (1 – x) = 13

3x -6 -1 +x = 13

3x +x = 13 +6 +1

4x = 20

x= 20 /4

x=5

H)6(4 – t) – 55 = - 5(2t+ 3)

24-6t-55=-10t-15

-6t+10t= -15 +55 +24

4t = 40 +24

4t = 64

t = 64 /4

t = 16

i) 5 – 4(x – 1) = 4x – 3(4x – 1) – 4

5 -4x +1 = 4x -12x +3 -4

-4x -4x -12x = 3 -4 +5 +1

-8x -12x = -1 +6

-20x = 5

x = 20 /5

x = 4