Respuesta :
Step-by-step explanation:
X2+ax+b=(x-9)(x+9)
X2+ax+b=x2-9x+9x-81
X2+ax+b=x2-81
therefore,a=0,b=(-81)
Then , ab = 0×-81 = 0
Answer:
B) 0
Step-by-step explanation:
x² + ax + b = (x – 9)(x + 9)
x² + ax + b = x² – 9x + 9x – 81
x² + ax + b = x² + 0x – 81
x²=x² +ax = +0x +b = -81
a = 0 b = -81
ab = 0(-81) = 0