Question

14.) If a + b = 5 and a2 + b2 = 13, find ab.​

Answer 1

Answer:

a + b = 5

squaring both sides

(a + b)^2 = 5^2

a^2 + b^2 + 2ab = 25

13 + 2ab = 25

2ab = 25 - 13

2ab = 12

ab = 12 / 2

ab = 6