Question

If x+y=7 and x-y=9, calculate the value of xy (x²-y²).

Answer 1

Answer:

answer = 67

Step-by-step explanation:

Given, x−y=7 and xy=9

   x−y=7

Squaring both sides, we get,

   (x−y)2=72

=>x2+y2−2xy=49

=>x2+y2−2(9)=49

=>x2+y2=49+18

=>x2+y2=67

Answer 2

Answer:

x =8 y =-1

xy(x-y) 2

value is 63