posted by Sammi .
The perimeter of a rectangle is 74 centimeters. The width is doubled and the length is halved. The new rectangle has a perimeter of 76 centimeters. Find the dimensions.
Okay, so in class we're learning about Systems of Equations. What are the equations for this? How do I define the variables?
2W + 2L = perimeter = 74
2W = 74 -2L
2(2W) + 2(L/2) = 76
Substitute 74 - 2L for 2W in the last equation and solve for L. Put that value in the first equation to find W. Check by putting both values into the last equation.