If the sum of two numbers is 22 and their difference is 8. Find the product of these two numbers?

Question: If the sum of two numbers is 22 and their difference is 8. Find the product of these two numbers?

Solution:
Let, two numbers are, a and b
a + b = 22
a - b = 8

We know,
ab = {(a + b)/2}² - {(a - b)/2}²
= {22/2}² - {8/2}²
= (11)² - (4)²
= 121 - 16
= 105
∴ ab = 105

So the product of these two numbers is 105