SOLUTION: the area of a rectangular slab of sidewalk is 45 square feet. its length is 3 feet more than four times the width.find the length and the width.
Let width be x feet
Then length =
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Question 738731: the area of a rectangular slab of sidewalk is 45 square feet. its length is 3 feet more than four times the width.find the length and the width.
Let width be x feet
Then length = 4x+3
Area = x*(4x+3)
which is equal to 45 (given)
Therefore
x*(4x+3)= 45
4x^2+3x = 45
4x^2 + 3x -45=0
4x^2 + 15x -12x -45=0
x*(4x+15) -3*(4x+15)=0
(x-3)(4x+15)=0
so x=3 or 15/4
Ans : Length = 15ft and width=3ft
Answer by mathstutor494(120) (Show Source): You can put this solution on YOUR website!
Let width be x feet
Then length = 4x+3
Area = x*(4x+3)which is equal to 45 (given)
Therefore
x*(4x+3)= 45
4x^2+3x = 45
4x^2 + 3x -45=0
4x^2 + 15x -12x -45=0
x*(4x+15) -3*(4x+15)=0
(x-3)(4x+15)=0
so x=3 or 15/4
Ans : Length = 15ft and width=3ft
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