SOLUTION: A rectangle has a length of 6 and a width 5x+8 . The area is 80 . what is x ?

Algebra ->  Rectangles -> SOLUTION: A rectangle has a length of 6 and a width 5x+8 . The area is 80 . what is x ?       Log On


   

Question 1049232: A rectangle has a length of 6 and a width 5x+8 . The area is 80 . what is x ?
Answer by MathLover1(20855) About Me  (Show Source):
You can put this solution on YOUR website!
if a length of 6 and a width 5x%2B8, and the area is 80, we have
6%285x%2B8%29=80
30x%2B48=80
30x=80-48
30x=32
x=32%2F30
x=16%2F15
then a width is
5x%2B8=5%2816%2F15%29%2B8
5x%2B8=%2816%2F3%29%2B8
5x%2B8=16%2F3%2B24%2F3
5x%2B8=40%2F3
check the area:
length%2Awidth=80
6%2A%2840%2F3%29=80
cross%286%292%2A%2840%2Fcross%283%291%29=80
2%2A40=80
80=80