Question

Resposta de x.(x-7)=-10

Answer 1

x.(x-7)=-10

x² - 7x = -10
x² -7x + 10 = 0

a = 1
b = -7
c = 10

Δ = b² -4 .a .c
Δ = (-7)² -4 . 1. 10
Δ = 49 - 40
Δ = 9

-b +- √Δ   /2 .a

-(-7) +- √9  / 2 . 1
7 +-  3  / 2

x' = 7 + 3   /2
x' = 10 / 2
x' = 5

x" = 7 - 3  /2
x" = 4  /2
x'' = 2

Resposta : S{ 5  e  2 }