Question 604674
length= L
width = W


L = 2W - 5
Area = length * width
42 = (2W - 5)*W
{{{42 = 2W^2 - 5W}}}
{{{0 = 2W^2 - 5W - 42}}}
0 = (2W + 7)*(W - 6)
2W + 7 = 0 or W - 6 = 0
2W = -7 or W = 6
W = -7/2 or W = 6
because the width can't be a negative number, we choose W = 6
L = 2W - 5 = 2 * 6 - 5 = 12 - 5 = 7


so the length of the rectangle is 7 centimeters and the width is 6 centimeters