I can find the answer, but need help setting it up well. The answer key gives me the answer, but doesn't show me how to set up the problem well.

Question

The sum of two numbers is eighty-seven. The larger number is seventeen less than three times the smaller number. Find the numbers.

Answer 1

The sum of two numbers is eighty-seven. The larger number is seventeen less than three times the smaller number. Find the numbers.

You have 2 unknowns----call them x and y.

You need 2 equations. Get these from the statements given:

"The sum of two numbers is eighty-seven"

x + y = 87

"The larger number is seventeen less than three times the smaller number."

3x - 17 = y

Solve this pair of equations using either combination or substitution. Example: Use the 2nd equation to replace y in the first:

x + (3x - 17) = 87

Simplify and solve for x, then use either equation to find y