SOLUTION: the length of rectangular lot is three times its width.If the length is increased by 5 feet and the width is decreased by 2 feet, the area of the lot is decreased by 21 square feet

Algebra ->  Customizable Word Problem Solvers  -> Geometry -> SOLUTION: the length of rectangular lot is three times its width.If the length is increased by 5 feet and the width is decreased by 2 feet, the area of the lot is decreased by 21 square feet      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 898178: the length of rectangular lot is three times its width.If the length is increased by 5 feet and the width is decreased by 2 feet, the area of the lot is decreased by 21 square feet. Find the dimension.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
w and L for dimensions.
Original lot, L=3w, meaning A for area is A=wL=3w%5E2

Rectangle of specified new dimensions,
L+5 and w-2;
The area is %28L%2B5%29%28w-2%29=wL%2B5w-2L-10

Description indicates wL%3EwL%2B5w-2L-10
AND
highlight_green%28wL-%28wL%2B5w-2L-10%29=21%29

STEPS TO SOLVE
wL-wL-5w%2B2L%2B10=21
2L-5w%2B10=21
2L-5w=11
substitute according to given L versus w
2%2A3w-5w=11
6w-5w=11
highlight%28w=11%29

Get the value of L from that:
L=3%2Aw
L=3%2A11
highlight%28L=33%29

Original rectangle is dimensions L=33 and w=11.
You can evaluate dimensions of the newer rectangle if desired.