Question

7x(x-1)=2(3x+1) ajudem ai galera

Answer 1

7x (x-1) = 2 (3x+1)
7x² - 7x = 6x + 2
7x² -7x - 6x - 2 = 0
7x² -13x - 2 = 0

a = 7
b = -13
c = -2

Δ = b² -4 .a .c 
Δ = (-13)² -4 . 7 . (-2)
Δ = 169 + 56
Δ = 225

-b +- √Δ   /2 . a
-(-13) +- √225    /2.7
13 +-  15    / 14

x' = 13 + 15   /14
x' = 28 /14
x' =  2

x" = 13 - 15   /14
x" = -2 /14     ÷2
x" = -1 /7

Resposta : S:{ 2  e -1/7 }

Answer 2

7x-7=6x+2
7x-6x=2+7
x=9
Tomara que esteja certo