Question

The difference of two numbers is 4 and their product is 165. Find the numbers. (by simultaneous linear equation)​

Answer 1

let two numbers be x and y

according to question,

x-y = 4 --------(1)

xy = 165 ---------(2)

putting the value of x from (2) to (1),

165/y -y = 4

165 - y² = 4y

y² + 4y - 165 = 0

y² + 15y -11y -165 =0

y (y+15) -11(y+15) =0

(y+15) (y-11) =0

y = -15 , 11

putting values of y in (1), we get,

x = -11 ,15

the two numbers are (-11,-15) or (15,11)