Math
posted by Mona on .
The perimeter of a rectangle is 46m. If the width were doubled and the length were increased by 12m, the perimeter would be 82m. What are the length and width of the rectangle?

original:
2L+ 2W = 46
L+W = 23
new one:
2(L+12) + 2(2W) = 82
2L + 24 + 4W = 82
L + 2W = 29
Subtract the 1st from the 2nd
W = 6
back in the 1st > L=17
original rectangle is 17 by 6
check: perimeter of original = 34 + 12 = 46
new rectangle is 29 by 12
perimeter of new = 2(29) + 2(12) = 82