Question

if a minus b equal to 0.9 and a b equal to 0.36 find a + b and a2-b2

Answer 1

a-b=0.9
ab=0.36
(a-b) ^2=(a+b)^2 -4ab
0.9^2+4(0.36)=(a+b)^2
0.81+1.44=(a+b)^2
(a+b)^2 =2.25
a+b=1.5
a^2 -b^2 =(a+b)(a-b)
=(1.5)(0.9)
1.35 is answer