SOLUTION: A length of the photograph is 7 cm longer than the width. Its area is 30 cm^2. Find the length and the width.

Algebra ->  Rectangles -> SOLUTION: A length of the photograph is 7 cm longer than the width. Its area is 30 cm^2. Find the length and the width.      Log On


   

Question 544706: A length of the photograph is 7 cm longer than the width. Its area is 30 cm^2. Find the length and the width.
Answer by JBarnum(2146) About Me  (Show Source):
You can put this solution on YOUR website!
A=L%2AW area=length times width
A=30
L=7+w
30=%287%2Bw%29%28w%29
30=7w%2Bw%5E2
w%5E2%2B7w-30=0 find two numbers that multiply to get -30 and add to get +7: +10 and -3, 10(-3)=-30, 10-3=7
%28w%2B10%29%28w-3%29=0 solve
w=-10w=3 width cant be negative
highlight%28w=3%29
L=7%2B%283%29
highlight%28L=10%29