Question

resolva as equaçoes abaixo:
a) x+5 = 18
b) 2x+ x = 7-10x
c) x + 12=2x+9
d) 3.(x-7)= 5x
e) 5.(x+1)=3.(1-x)
f) 4.(x-6)= -3
g) 4y - 10+y=18+7y

Answer 1

$a) x=18-5=13 \\ b)3x+10x=7 --->13x=7 --->x= \frac{7}{13} \\ c) x-2x=9-12 ----> -x=-3*(-1) ---> x=3 \\d) 3x-21=5x -->3x-5x=21 --> -2x=21 -->x=-21/2$
$e)5x+5=3-3x -->5x+3x=-5+3 -->8x=-2 --> \\x=-2/8 -->x=-1/4$
$f) 4x-24=-3 \\4x=24-3 \\ 4x=21 \\ x=21/4$
$g) 4y+y-7y=18+10 \\-2y=28 \\ y=28/-2 \\ y=-14$

Answer 2

a) x+5=18
x=18-5
x=13

b)
2x+x=7-10x
13x+10x=7
23x=7
x=7/23

c)x+12=2x+9
x-2x=9-12
-x=-3  (multiplica os dois lados por -1)
x=3

d)3(x-7)=5x
3x-21=5x
-21=5x-3x
2x=-21
x=-21/2

e) 5.(x+1)=3.(1-x)
5x+5=3-3x
5x+3x=3-5
8x=-2
x=-2/8
x=-1/4

f) 4.(x-6)= -3
4x-24=-3
4x=24-3
4x=21
x=21/4

g) 4y - 10+y=18+7y

4y+y-7y=18+10
-2y=28
y=-14