Question

x ao quadrado + x -7 = 5

Answer 1

x² + x - 7 = 5
x² + x - 12 = 0
Δ = 1 + 48
Δ = 49

x = -1 +-√49/2
x = -1 +-7/2
x' = -1 +7/2
x' = 6/2 = 3
x'' = -1-7/2
x'' = -8/2 = - 4     ok