Question

Resolva as seguintes equações do primeiro grau :

A) 5(2×-4)=4+6×

B) 3(2×+1)=-5+4×

C) 3(2×-1)=-5-4×

D)8(×+2)=3(×+4)-6

E) 4(2×-3)=-2(3×-8)

F) 4(3×+1)=-3 (×-5)+7

G) 2×+3×=-45

Answer 1

A) $5(2x-4)=4+6x$

$10x-20=4+6x\\10x-6x=4+20\\4x=24\\4x:4=24:4\\x=6$

B) $3(2x+1)=-5+4x\\6x+3=-5+4x\\6x-4x=-5-3\\2x=-8\\2x:2=-8:2\\x=-8:2\\x=-4$

C) $3(2x+1)=-5-4x\\6x-3=-5-4x\\6x+4x=-5+3\\10x=-2\\10x:10=-2:10\\x=-\frac{2}{10}$$x=-\frac{1}{5}$

D) $8(x+2)=3(x+4)-6\\8x+16=3x+12-6\\8x+16=3x+6\\8x-3x=6-16\\5x=-10\\5x:5=-10:5\\x=-2$

E) $4(2x-3)=-2(3x-8)\\8x-12=-6x+16\\8x+6x=16+12\\14x=28\\14x:14=28:14\\x=2$

F) $4(3x+1)=-3 (x-5)+7\\12x+4=-3x+15+7\\12x+4=-3x+22\\12x+3x=22-4\\15x=18\\15x:15=18:15\\x=\frac{18}{15}\\ x=\frac{6}{5}$

G) $2x+3x=-45\\5x=-45\\5x:5=-45:5\\x=-45:5\\x=-9$