Question

If a+b=13 and ab=40, find a²+b²

Answer 1

(a+b)^2=(13)^2
a^2+b^2+2ab = 169
a^2+b^2=169-2*40

So answer is 89

Answer 2

Answer:

89

Step-by-step explanation:

a²+b²=(a+b)²-2ab=13²-2x40=89