Question

Q16.
1 point
Ifx - y = -8, xy = –12, then X3 – y3 is equal to
0 -244
O -240
0
-224
O -260​

Answer 1

Answer:

The correct answer is -224

Step-by-step explanation:

x-y=-8

x=y-8------(1)

put in xy= -12

(y-8)y= -12

y^2-8y= -12

y^2-8y+12=0

y^2-6y-2y+12=0

y(y-6) -2(y-6) =0

(y-2)(y-6)=0

.: y=2 or y=6

put in equation (1)

x=2-8 or x=6-8

x=-6 or x=-2

x^3-y^3 = (-6)^3-(2)^3

= -216-8

= -224

x^3-y^3 = (-2)^3-(6)^3

= -8 -216

= -224