posted by 8th Grade .
How do you solve this Pre-Algebra problem:
$1.25x + $2.25y = $916
x + y = 560
This is a system of equations. There are three ways you can solve these types of problems, graphing, substitution, or elimination. I'll use eliminations for this one. Elimination means that you try to eliminate one of the variables.
First, I multiply the second equation by 1.25:
1.25x + 2.25y = 916
1.25x + 1.25y = 700
Now, subtract the two equations:
1y = 216
y = 216
Substitute 216 into y of one of the equations:
1.25x + 2.25(216) = 916
1.25x + 486 = 916
1.25x = 430
x = 344
The answer is (344, 216).
Check your answer by substituting these values into the equations:
1.25(344) + 2.25(216) = 916
344 + 216 = 560
the ratio of the length to the width of a rectangular field is 3 to 2, if the field is 120 yards long, how wide is the field.