Q. The area of a photograph is 40 square inches. The perimeter is 26 inches. What are the dimensions of the photograph?___ inches by ___ inches
Area Equation: Let's denote the length and width of the photograph as l and w respectively. Since the photograph is a rectangle, the area A is given by A=l×w.Given the area of the photograph is 40 square inches, we have the equation:40=l×w
Perimeter Equation: The perimeter P of a rectangle is given by P=2l+2w.Given the perimeter of the photograph is 26 inches, we have the equation:26=2l+2w
Solving System of Equations: To find the dimensions l and w, we need to solve the system of equations:1. 40=l×w2. 26=2l+2wLet's simplify the second equation by dividing all terms by 2:13=l+w
Expressing Width in Terms of Length: Now we have two equations:1. 40=l×w2. 13=l+wFrom the second equation, we can express w in terms of l:w=13−l
Quadratic Equation: Substitute w from the fourth step into the first equation:40=l×(13−l)This gives us a quadratic equation:40=13l−l2Rearranging the terms, we get:l2−13l+40=0
Factoring Quadratic Equation: We need to factor the quadratic equation:l2−13l+40=(l−5)(l−8)=0This gives us two possible solutions for l:l=5 or l=8
First Solution: l=5: If l=5, then substituting back into w=13−l gives us:w=13−5w=8
Second Solution: l=8: If l=8, then substituting back into w=13−l gives us:w=13−8w=5
Valid Solutions: Both solutions (l=5,w=8) and (l=8,w=5) are valid since they are interchangeable (length and width can be swapped for a rectangle). They both satisfy the original equations for area and perimeter.
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