if one side of a square (in metre ) is represented by 18x -20 and then adjacent side in metre represent by 42-13x find the length of the side of the square
Answers
Answer:
You need to use your information about area and perimeter to set up two equations with two variables representing length and width of the rectangle. Then you will set up a quadratic equation. Let's use L for the length and W for the width of the rectangle:
For the perimeter:
2L + 2W = 66 or
L + W = 33 or
W = 33 - L
For the area:
LW = 252
Now substitute W = 33 - L from the first equation into the second one:
L(33 - L) = 252 or
33L - L2 = 252 or
L2 - 33L + 252 = 0
This can be solved by factoring, or by using the quadratic equation.
By factoring:
(L - 12)(L - 21) = 0 or
L = 12, or L = 21
In this case, let's use 21 because length is usually the longer dimension. Now we substitute L = 21 into the first equation to find W.
W = 33 - 21 or
W = 12
Your answers are: Length = 21 and Width = 12