Question

b) 10x²-72x-64=0
c) x²-x-20​

Answer 1

Resposta:
B); 10x² + 72x - 64 = 0(:2)
5x² + 36x - 32 = 0
Delta = b² - 4ac
Delta = 1296 - 4(5)(-32)
Delta = 1296 + 640
Delta = 1936
X = (-b +- raiz delta) / 2a
X = (-36 +- 44) / 10
x' = (-36 + 44) / 10 = 8/10 = 4/5
x" = (-36 - 44) = -80/10 = -8
"C)

Resposta

S={-4 e 5}

Explicação passo-a-passo:

a=1 b= -1 c = -20

delta=b^2-4ac

delta=-1^2-4.1.-20

delta=1+80

delta=81

x=-b+ou-raizde81/2.b

x´=1+9/-2

x´=10/-2

x´=5

x´´=1-9/-2

x´´=8/-2

x´´=-4