Question

Calcule (x+5)2+(x+9)*(x - 9)+(2x+1)*(5x - 4)
Obs: Me manda o cálculo.​

Answer 1

Resposta:

( x+ 5 ) 2 + ( x+9 ) * ( x-9 ) + ( 2x + 1 ) * ( 5x - 4)

2x + 10 + x² - 9x + 9x - 81 + 10x - 8x + 5x - 4

2x - 9x + 9x + 10x - 8x + 5x + x² + 10 - 4 - 81

9x + x² - 75

a = 1

b = 9

c = - 75

Δ = b² - 4.a.c

Δ = 9² - 4.1.(-75)

Δ = 81 + 300

Δ = 381

x = -b ±√Δ

        2.a

x = -9 ±√381

        2.1

x = -9 ± 19,51

        2.1

x¹ = - 9 + 19,51 = 10,51 = 5,25

             2              2

x² = - 9 - 19,51 = - 28,51 = -14,25

             2                2