
Karen L. answered 03/24/17
Tutor
5
(21)
Professional ACT MATH Tutor for High School Students
I find it helpful to draw a rectangle and label L for length and W for width. The perimeter is 2 Lengths + 2 Widths = 128. Simplify the equation and solve for either variable (I choose to solve for L).
2L + 2W = 128 Perimeter
L + W = 64 Simplify
L = 64 - W Solve for L
And 360 is equivalent to 5L + 7W.
5L + 7W = 360
Substitute the known variable into the second equation.
5(64 - W) + 7W = 360 Substitute
320 - 5W + 7W = 360 Combine like terms
320 + 2W = 360 Subtract 320 from both sides
2W = 40 Divide from both sides
W = 20 ***
Substitute the known value back into the original equation.
L + (20) = 64 Subtract from both sides
L = 44 ****
Does that make sense?