Question

Resolva as equações :

A) 8(x-3)+2(5-x)=-x
B) -2(x-5)-3(2x+7)=10-x
C) 2(-2x+3)-5(2-x)=3(2x+3)
D) y-[5-(7-y)]=(y+6)+2y

Answer 1

Resolva as equações :A
 8(x-3)+2(5-x)=-x
8x -24 + 10 - 2x = - x
8x - 2x - 24 + 10 = - x
6x - 14 = - x
6x = - x + 14
6x + x = 14
7x = 14
x = 14/7
x = 2

B)
 -2(x-5)-3(2x+7)=10-x
- 2x+10 - 6x - 21 = 10 - x
- 2x - 6x + 10 - 21 = 10 - x
- 8x - 11 = 10 - x
- 8x - 11 + x = 10
- 8x + x = 10 + 11
- 7x = 21
x = 21/-7
x = - 21/7
x = - 3



C)
 
2(-2x+3)-5(2-x)=3(2x+3)
- 4x + 6 - 10 + 5x = 6x + 9
- 4x  - 4 + 5x = 6x + 9
- 4x + 5x - 4 = 6x + 9
1x - 4 = 6x + 9
1x - 4 - 6x = 9
1x - 6x = 9 + 4
- 5x = 13
x = 13/-5
x = - 13/5

D)
 y-[5-(7-y)]=(y+6)+2y


y - [5- (7 - y)] = (y + 6) + 2y 
y - [5  - 7 + y] = y + 6 + 2y
y - [ - 2 + y] = y + 2y + 6
y   + 2  - y   = 3y + 6
y - y + 2 = 3y + 6
    0  + 2 = 3y + 6

2 = 3y + 6
2 - 6 = 3y
- 4 = 3y

3y = - 4
y = - 4/3