SOLUTION: The product of two whole numbers is 90. One number is 2.5 times as great as the other. What are the two numbers?

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Question 826650: The product of two whole numbers is 90. One number is 2.5 times as great as the other. What are the two numbers?
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

let two numbers be x and y
if the product of two whole numbers is 90, then we have
xy=90........eq.1

if one number (let it be x) is 2.5 times as great as the other (let it be y), then we have
x=2.5%2Ay..........eq.2
now solve the system:
xy=90........eq.1
x=2.5%2Ay..........eq.2
________________________
xy=90........eq.1.............substitute x from eq.2
2.5y%2Ay=90........solve for y
y%5E2=90%2F2.5
y%5E2=36
y=sqrt%2836%29
y=6 or y=-6
now find x
x=2.5%2Ay=> x=2.5%2A6=> x=15
or
x=2.5%2Ay=> x=2.5%2A%28-6%29=>x=-15

so, your numbers are
x=15 and y=6
or
x=-15 and y=-6