SOLUTION: the question is write and solve an equation to find the length and with of the rectangle whose width os 3 less than the length. the area is 4cm
Question 444661: the question is write and solve an equation to find the length and with of the rectangle whose width os 3 less than the length. the area is 4cm Found 2 solutions by oberobic, solver91311:Answer by oberobic(2304) (Show Source):
You can put this solution on YOUR website! The area of a rectangle = length * width.
A = L * W
A = 4 (given)
W = L -3 (given)
or
L = W + 3
.
Substitute what we know now.
.
A = L*W
4 = L* (L-3)
4 = L^2 -3L
Subtract 4 from both sides
.
0 = L^2 -3L -4
L^2 -3L -4 = 0
.
Factor
(L -4)(L +1) = 0
.
L = 4 or L = -1
Well, we cannot have negative length, so L = 4.
.
Looking back, the only possible value for W = 1.
.
Done.
Let represent the width of the rectangle (note spelling of width, not "with"). Then must represent the length. Since the area is the length times the width, represents the area. You state that the area is 4 cm but that is clearly wrong. Area is measured in square units, not linear units, hence the area must be 4 square centimeters.
And in standard form:
Just solve for , discard the negative root (since you are trying to determine a postive measure of length), and then calculate
John
My calculator said it, I believe it, that settles it
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