Question

Sum of 12.5 and product of 36

I mean 2 variables add up to 12.5
and multiply to 12.5
(x+y)=12.5
X ×Y=36
What is value of x and y​

Answer 1

(4.5, 8) and (8, 4.5)

Explanation:

Given the equations

(x+y)=12.5 ... 1

X ×Y=36 .... 2

From 2, Y = 36/X

Substitute into 1

x+ 36/x = 12.5

x^2 + 36 = 12.5x

x^2 - 12.5x + 36 = 0

10x^2 - 125x + 360 = 0

2x^2 - 25x + 72 = 0

Factorize

2x^2 - 16x - 9x + 72 = 0

2x(x-8)-9(x-8) = 0

2x-9 = 0 and x-8 = 0

x = 9/2 and x = 8

when x = 9/2

Y = 36/(9/2)

Y = 36 * 2/9

Y = 8

When x = 8

Y = 36/X

Y = 36/8

Y = 4.5

Hence the solutions are (4.5, 8) and (8, 4.5)