Question

8 questões valendo 21 pontos! Sobre equações do 1º grau:

A) 23-16=14-17x

B) 10y-5(1+y)=3(2y-2)-20

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

D) 2x+3(x-5)=4x+9

E) 2(x+1)-3(2x-5)=6x-3

F) 3x+5=2

G) x-(2x-1)=23

H) 2x-(x-1)=5-(x-3)

Answer 1

a)23-16=14-17x
17x=14+16-23
17x=7
x=7/17

B)10y-5(1+y)=3(2y-2)-20
10y-5+5y=6y-6-20
15y-5=6y-26
15y-6y=-26+5
9y=-21
y=-21/9
y= -7/3

C)x-5/10+1-2x/5=3-x/4
mmc(10,5)=10
(x-5+2-4x)/10=(3-x)/4
Multiplica cruzado. 
30-0x=-12-12x
-10x+12x=-12-30
-2x=-42
x=-42/-2
x=21