Q:

50 POINTS! I MARK BRAINLEST AND SAY THANKS!Y * x = 20y + x = 9 what number does y equal?what number does x equal?

Accepted Solution

A:
y *x =20

y +x =9

rewrite 1st eq. as y = 20/x

subsituute that into 2nd eq.

20/x +x =9

multiply each term by X

20 +x^2 = 9x
 subtract 9x from each side:

x^2 - 9x +20 = 0

now factor:

(x-5) (x-4) = 0

solve for x
5-5 = 0
 4-4 = 0

so X can be 4 or 5

replace x into equations and solve for Y

 so when X = 4, Y = 5
 When X = 5, Y = 4

x= 5,4
y = 4,5