SOLUTION: the rectangle has an area of 252 sq ft. side lengths are 21-5x and 7. find the value of x

Question 1096315: the rectangle has an area of 252 sq ft. side lengths are 21-5x and 7. find the value of x
Found 2 solutions by Rhodium, greenestamps:
Answer by Rhodium(14) (Show Source): You can put this solution on YOUR website!
As an equation, this is:
252 = (21 - 5x) * 7
Solve for x:
252 / 7 = (21 - 5x) * 7 / 7
252 / 7 = 21 - 5x
252 / 7 - 21 = 21 - 5x - 21
252 / 7 - 21 = 5x
x = (252 / 7 - 21) / 5
Simplify:
x = (252 / 7 - 21) / 5
x = (36 - 21) / 5
x = 15 / 5
x = 3
Convert to sq ft:
x = 3 sq ft.
Answer by greenestamps(13200) (Show Source): You can put this solution on YOUR website!

The sign on tutor Rhodium's answer is wrong. The work he shows to get the answer is also more difficult than it needs to be.

x is -3, not 3.
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