Question

Resolva as equaçoes do primeiro grau :
a}3x-9=7+x
b}3x+12=0
c}-9+5x=-3-2x
d}2x+3+5x-15=3x+3+x
e}2*{x+6}=4*{x+2}

Answer 1

a) 3x-x = 7+9
2x = 16
x = 16/2
x = 8

b) 3x = -12
x =-12/3
x = -4

c) 5x+2x = -3+9
7x = 6
x = 6/7

d) 2x+5x-3x-x = 3-3+15
3x = 15
x = 15/3
x = 5

e) 2x+12=4x+8
2x-4x =8-12
-2x = -4
x = -4/-2
x = 2

Answer 2

a) 3x - 9 = 7 + x
3x - x = 7 + 9
2x = 16
x = 16/2
x = 8
b) 3x + 12 = 0
3x = 0 - 12
3x = -12
c) -9 + 5x = - 3 - 2x
+ 5x + 2x = - 3 + 9
7x = + 6
x = 6/7
d) 2x + 3 + 5x - 15 = 3x + 3 + x
2x + 5x - 3x  - x = +3 - 3 + 15
7x - 3x - 3x = + 15
- 4x - 3x = + 15
- 7x = + 15(multiplicando por - 1
7x = - 15
x = - 15/7
e) 2 . (x + 6 ) = 4. (x + 2)
2x + 12 = 4x + 8
2x - 4x = 8 - 12
-2x = - 4 (multiplicando por -1)
2x = 4
x = 4/2
x = 2