The area of a rectangular cutting board is 80 square inches. The perimeter is 36 inches. What are the dimensions of the cutting board?___ inches by ___ inches
Q. The area of a rectangular cutting board is 80 square inches. The perimeter is 36 inches. What are the dimensions of the cutting board?___ inches by ___ inches
Define Variables: Let l be the length and w be the width of the rectangular cutting board.The area of a rectangle is given by the formula A=l×w.
Area and Perimeter Formulas: The area of the cutting board is given as 80 square inches.Substitute 80 for A in the formula A=l×w.80=l×w
Substitute Values: The perimeter of a rectangle is given by the formula P=2l+2w.The perimeter of the cutting board is given as 36 inches.Substitute 36 for P in the formula P=2l+2w.36=2l+2w
Simplify Perimeter Equation: Divide the perimeter equation by 2 to simplify.236=22l+2w18=l+w
Solve System of Equations: We now have two equations with two variables:80=l×w (Area equation)18=l+w (Perimeter equation)We can solve this system of equations to find the values of l and w.
Express Width in Terms of Length: Rearrange the perimeter equation to express w in terms of l.w=18−l
Substitute into Area Equation: Substitute w=18−l into the area equation 80=l×w.80=l×(18−l)
Form Quadratic Equation: Expand the equation and move all terms to one side to form a quadratic equation.80=18l−l20=l2−18l+80
Factor Quadratic Equation: Factor the quadratic equation.0=(l−10)(l−8)
Solve for Length: Solve for l by setting each factor equal to zero.l−10=0 or l−8=0l=10 or l=8
Find Valid Solutions: If l=10, then w=18−l=18−10=8. If l=8, then w=18−l=18−8=10. Both pairs (10,8) and (8,10) are valid solutions since a rectangle can have its length and width interchanged.
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