Question

a+b=9 and ab= -22 , then find the value of a^2-b^2

Answer 1

Answer:

(a+b)2=a2+2ab+b2

81=-44+a2+b2

a2+b2=125

(a-b)2=a2-2ab+b2

(a-b)2=125-2(-22)

(a-b)2=169

(a-b)=13

a2-b2=(a+b)(a-b)

a2-b2=(9)(13)

a2-b2=117

Therefore, a2-b2=117

I hope this might help you:)