Question 694167: area of a rectangle: A=LW
The are of this rectangle is 39 square units. Find its length (the horizontal side ) and width (the vertical side)
length)x+5
width) x-5
a) write an equation using the formula and the given information.
39=? (do not multiply)
b) solve the equation, giving only the solution(s) that make sense in the problem. The solution for x is ?
c) use the solution to find the indicated dimensions of the figure.
Length=? Width=?
Found 2 solutions by ShaunaJS, Jasmin15:
Answer by ShaunaJS(1)   (Show Source):
You can put this solution on YOUR website! (x+5)(x-5)=39
x^2-5x+5x-25=39
x^2-25=39
x^2-64=0
x^2-8x+8x-64=0
x(x-8)+8(x-8)=0
(x-8)(x+8)=0
x-8=0 or x+8=0
x=8 or x=-8
8+5=13, 8-5=3, -8+5=-3, -8-5=-13
You can't have negatives as a length or width.
So x=8
Length=8+5
Width=8-5
Length=13
Width=3
Answer by Jasmin15(1) (Show Source):
You can put this solution on YOUR website! (x+5) (x-5)=39
x^2-5x+5x-25=39
x^2-25=39
x^2-64=0
x^2-8x+8x-64=0
x(x-8)+8(x-8)
(x+8)(x-8)
x=-8 or x=8
8+5=13, 8-5=3, -8+5=-3, -8-5=-13,
you can not have a negative number as a length or width, so x=8
Length=8+5
Width=8-5
Length=13
Width=3
|
|
|
