Question

Resolva as equações
a) 4 ( x+1 ) = 12
b) 5 ( 3-x ) - 4x = 18
c) 9x -3 ( 2x +2 ) = 15
d) 2,5 ( x-2 ) - 1,5x = 1
e) 3,5x +8 = 2 ( x+7 )
f ) 6 ( 3x ) +2 -8 = -2
g) -3 ( x -5 ) -2 ( 2x +1 ) = -8

Answer 1

a) 4 ( x+1 )=12
4(x+1)÷4=12÷4
x+1=3
x=3-1
x=2

b) 5(3-x)-4x=18
5x3-5x-4x=18
15-5x-4x=18
15-9x=18
-9x=18-15
-9x=3
x=$- \frac{3}{9}$
x=-$\frac{1}{3}$

c) 9x-3(2x+2)=15
9x-3x2x-3x2=15
9x-6x-6=15
3x-6=15
3x=15+6
3x=21
3x÷3=21÷3
x=7

d) 2,5(x-2)-1,5x=1
2.5x-2.5x2-1,5x=1
2.5x-5-1,5x=1
(2.5-1.5)x-5=1
1x-5=1
x-5=1
x=1+5
x=6

e) 3,5x+8=2(x+7)
3.5x+8=2x+2x7
3.5x+8=2x+14
3.5x-2x=14-8
1.5x=6
x=4


f ) 6(3x)+2-8=-2
18x+2-8=-2
18-6=-2
18x=-2+6
18x=4
x=$\frac{4}{18}$
x=$\frac{2}{9}$

g) -3(x-5)-2(2x +1)=-8
-3x-3x(-5)-2x2x2-2=-8
-3x+15-4x-2=-8
-7x+13=-8
-7x=-8-13
-7x=-21
x=3