If a2+b2=14 and ab=3, find the value of 2(a+b)2−5(a−b)2.
If a + b = 10 and ab = 16, find the value of a2−ab+b2 and a2+ab+b2.
If a = 2, b = − 2, find the value of:
(i) a2 + b2 (ii) a2 + ab + b2 (iii) a2 − b2