SOLUTION: The area of rectangle ABCD is {{{ 20 cm^2 }}}. If the width is 7 cm more than 3 times the length, what are the dimensions of the triangle? Use a polynomial equation to solve the

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: The area of rectangle ABCD is {{{ 20 cm^2 }}}. If the width is 7 cm more than 3 times the length, what are the dimensions of the triangle? Use a polynomial equation to solve the      Log On


   



Question 301468: The area of rectangle ABCD is +20+cm%5E2+. If the width is 7 cm more than 3 times the length, what are the dimensions of the triangle?
Use a polynomial equation to solve the problem
It would also be helpful if you included the initial equation so I could understand it better.

Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
AREA=L*W
W=3L+7
20=L(3L+7)
20=3L^2+7L
3L^2+7L-20)=0
(3L-5)(X+4)=0
3L-5=0
3L=5
L=5/3 ANS.
W=3*5/3+7=5+7=12 ANS.
PROOF:
20=5/3*12
20=5*4
20=20