Q. An envelope has an area of 50 square inches and a perimeter of 30 inches. What are the dimensions of the envelope?___ inches by ___ inches
Define Variables: Let's denote the length of the envelope as l and the width as w. The area A of a rectangle is given by the formula A=l×w, and the perimeter P is given by P=2l+2w.
Area and Perimeter Equations: We are given the area of the envelope as 50 square inches, so we have the equation l×w=50.
Solve System of Equations: We are also given the perimeter of the envelope as 30 inches, so we have the equation 2l+2w=30. We can simplify this equation by dividing both sides by 2, which gives us l+w=15.
Quadratic Equation Simplification: Now we have a system of two equations:1. l×w=502. l+w=15We can solve this system by expressing one variable in terms of the other using the second equation. Let's solve for w: w=15−l.
Factor Quadratic Equation: Substitute w from the second equation into the first equation:l×(15−l)=50This simplifies to a quadratic equation:l2−15l+50=0
Find Possible Solutions: To solve the quadratic equation, we can factor it:(l−10)(l−5)=0This gives us two possible solutions for l: l=10 or l=5.
Find Possible Solutions: To solve the quadratic equation, we can factor it:(l−10)(l−5)=0This gives us two possible solutions for l: l=10 or l=5.If l=10, then w=15−l=15−10=5.If l=5, then w=15−l=15−5=10.Both pairs (l=10, w=5) and (l=5, l1) are valid solutions because they are interchangeable due to the envelope's length and width being relative terms.
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