If a + b = 10 and ab = 16, find the value of a2−ab+b2 and a2+ab+b2.
a + b = 10, ab = 16
Squaring,
(a+b)2=(10)2⇒ a2+b2+2ab=100⇒ a2+b2+2×16=100⇒ a2+b2+32=100∴ a2+b2=100−32=68Now, a2−ab+b2=a2+b2−ab=68−16=52and a2+ab+b2=a2+b2+ab=68+16=84