Question

If (a-b)=7 and ab=9 then (a2+b2)=?

Answer 1

Answer:

67 i67 is the correct answer

Answer 2

Step-by-step explanation:

a-b=7 _____(1)

ab=9  _____(2)

(a²+b²) = (a+b)² = a²+b²+2ab

now, in (1)

a-b=7

a=7-b____(3)

On substituting (2) and (3)

(7-b)² +b²+2×9 = 49 +2b²-14b+18 = 2b²-14b+67