Q. A rectangular bathroom mirror has an area of 27 square feet and a perimeter of 24 feet. What are the dimensions of the mirror?___ feet by ___ feet
Define Variables: Let's denote the length of the mirror as L feet and the width as W feet. We know that the area (A) of a rectangle is given by A=L×W and the perimeter (P) is given by P=2L+2W. We are given that A=27 square feet and P=24 feet. We need to set up two equations based on these formulas and solve for L and W.
Area Equation: First, let's write down the area equation with the given value:A=L×W27=L×W
Perimeter Equation: Now, let's write down the perimeter equation with the given value:P=2L+2W24=2L+2W
Simplify Perimeter: We can simplify the perimeter equation by dividing all terms by 2 to make it easier to solve:24÷2=L+W12=L+W
System of Equations: Now we have a system of two equations:1) 27=L×W2) 12=L+WWe can solve this system by expressing one variable in terms of the other using the second equation and then substituting it into the first equation.
Express W in Terms of L: Let's express W in terms of L using the second equation:W=12−LNow we can substitute this expression for W into the first equation.
Substitute W in Area Equation: Substituting W in the area equation, we get:27=L×(12−L)This is a quadratic equation: L2−12L+27=0We need to solve this quadratic equation for L.
Solve Quadratic Equation: To solve the quadratic equation, we can factor it if possible:(L−3)(L−9)=0This gives us two possible solutions for L: L=3 or L=9.
Factor Quadratic Equation: If L=3, then using the equation W=12−L, we find that W=12−3=9. If L=9, then W=12−9=3. So the dimensions of the mirror can be 3 feet by 9 feet or 9 feet by 3 feet, which are essentially the same since it's a rectangle and the sides can be interchanged.
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