Question

7 x ao quadrado - 3x - 21 x + 9 = ​

Answer 1

Resposta:

7X² - 3X - 21X + 9 =

7X² -24X +9 =

Δ = b²-4ac

Δ = (-24)² -4 . 7 . 9

Δ = 576 -252

Δ = 324

X = -b ± √Δ / 2.a

X = -(-24) ± √324 / 2.7

X = 24 ± 18 / 14

X1 = 24 + 18 / 14 = 42/14 = 3

X2 = 24 - 18 /14 = 6/14 = 3/7