SOLUTION: Twice a number is 8 less than its square. What is the number?
The length of a rectangle is 5m more than its width. What is the width of the rectangle if its area is 84 m^?
Li
Question 553546: Twice a number is 8 less than its square. What is the number?
The length of a rectangle is 5m more than its width. What is the width of the rectangle if its area is 84 m^?
List any necessary restrictions on the variable for the fraction to be defined.
I have 2 different examples: EX(1) (x-1)divided by 2x+8 EX(2) x(x+2) divided by (x-3)(x+5) Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Twice a number is 8 less than its square. What is the number?
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Let the number be "x":
Equation:
2x = x^2-8
x^2-2x-8 = 0
(x-4)(x+2) = 0
x = 4 or x = -2
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The length of a rectangle is 5m more than its width. What is the width of the rectangle if its area is 84 m^?
L = W + 5
Area = 84 sq meters
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Equation:
LW = 84
Substitute for "L" and solve for "W":
(W+5)W = 84
W^2 + 5W - 84 = 0
(W+12)(W-7) = 0
Positive solution:
W = 7 meters (width)
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Solve for "L"
L = W + 5
L = 12 meters (length)
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List any necessary restrictions on the variable for the fraction to be defined.
I have 2 different examples:
EX(1) (x-1)divided by 2x+8
2x+8 cannot be zero
x cannot be -8/2 = -4
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EX(2) x(x+2) divided by (x-3)(x+5)
(x-3)(x+5) cannot be zero
x cannot be 3
x cannot be -5
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Cheers,
stan H.
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