Question

Linear equation in one variable

Q. sum
of two numbers is 100 and their difference is 37 then the difference of their
square is 

Answer 1

let the no. be x and y, then
x+y = 100
x-y = 37
x^{2} - y^{2} = (x+y) (x-y) = 100 *37= 3700

Answer 2

let first number = x
second number = y
x+y = 100-------------(1)
x-y = 37 ------(2)
(1)+(2)
2x = 137
x = 137/2
y = 63/2
x² - y² = 18769/4 - 3969/4
          = 14800/4
 x² - y² = 3700