SOLUTION: the product of two positive rational numbers is 36/5. If one number is 4/5 of the other. What are the two numbers?

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Question 1144040: the product of two positive rational numbers is 36/5. If one number is 4/5 of the other. What are the two numbers?
Found 2 solutions by richwmiller, Theo:
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
x*4*x/5=36/5
x^2=9
x=3
3 and 12/5

Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
let x = one of the numbers.
let y = the other number.
x * y = 36/5
x = 4/5 * y
therefore x * y = 36/5 becomes 4/5 * y * y = 36/5
simplify to get 4/5 * y^2 = 36/5
multiply both sides of this equation by 5/4 to get:
y^2 = 36/5 * 5/4 = 9
solve for y to get y = 3
since x = 4/5 * y, then x = 4/5 * 3 = 12/5
the two numbers are 12/5 and 3.
12/5 * 3 = 36/5 so that checks out.
12/5 = 4/5 * 3 = 12/5 so that checks out.
the two numbers are 12/5 and 3.
12/5 * 3 = 36/5
(12/5)/3 = 12/5 * 1/3 = 12/15 * (1/3) / (1/3) = 4/5 which means that 12/5 is equal to 4/5 * 3.
your solution is that the two numbers are 12/5 and 3.