Question

Equações de 1º Grau
A) 3(6x+7)-2(x-1)=70
B) 8x+6-3=4+3x
C) 6(2x+6)-2(x+10)=x+4
D) 6(2x+6)-2(x+10)=x+4
E) 8(2x+7)-6(x-3)=100
F) 7(4x+6)-8(x+3)=2(x+7)
G) 2(10+8x)=60
H) 8+3(4x-7)+6=40+2x
I) 7(3+2x)+2(x-10)x+40
J) 2(6x+7)+8(x+10)=90

Answer 1

A) 3(6x+7)-2(x-1)=70
18x+21-2x+2=70
18x-2x=70-21-2
16x=47
x=47/16
x=2,9375

B) 8x+6-3=4+3x
8x-3x=4-6+3
5x=1
x=1/5 = 0,2

C) 6(2x+6)-2(x+10)=x+4
12x+36-2x-20=x+4
12x-2x-x=4-36+20
9x=-12
x=-12/9 ⇒ -4/3 = -1,33..

E) 8(2x+7)-6(x-3)=100
16x+56-6x+18=100
16x-6x=100-56-18
10x=26
x=26/10
x=2,6

F) 7(4x+6)-8(x+3)=2(x+7)
28x+42-8x-24=2x+14
28x-8x-2x=14-42+24
18x=-4
x=-4/18⇒-2/9 = -0.22..

G) 2(10+8x)=60
20+16x=60
16x=60-20
16x=40
x=40/16 ⇒ 20/8 ⇒ 10/4 ⇒ 5/2 = 2,5

H) 8+3(4x-7)+6=40+2x
8+12x-21+6=40+2x
12x-2x=40-8-12+21-6
10x=35
x=35/10 ⇒ 7/2 = 3,5

I) 7(3+2x)+2(x-10)=x+40
21+14x+2x-20=x+40
14x+2x-x=40-21+20
15x=39
x=39/15 ⇒ 13/5 = 2,6

J) 2(6x+7)+8(x+10)=90
12x+14+8x+80=90
12x+8x=90-14-80
20x=-4
x=-4/20 ⇒ -1/5 = -0,20