Question

x sobre 2 - 8x + 7 = 0​

Answer 1

x² - 8x + 7 = 0 → ∆ = (-8)² - 4 × 1 × 7 → ∆ = 64 - 28 → ∆ = 36

x = -(-8) ± √36 → x = 8 ± 6

2 × 1 2

x' = 8 + 6 → x' = 14 → x = 7

2 2

x" = 8 - 6 → x" = 2 → x" = 2

2 2

Espero ter ajudado!!!