Q. 4. The length of a rectangle is 1 meter less than its width. The area of the rectangle is 42 square meters. Find the dimensions of the rectangle.
Define Variables: Let's call the width of the rectangle w and the length l. We know that the length is 1 meter less than the width, so we can write l=w−1.
Calculate Area: The area of the rectangle is given by the formula Area=length×width, which is 42=l×w. Substituting l with w−1, we get 42=(w−1)×w.
Solve Quadratic Equation: Now we need to solve the quadratic equation 42=w2−w. Moving all terms to one side, we get w2−w−42=0.
Factorize Equation: To solve the quadratic equation, we can factor it. We're looking for two numbers that multiply to −42 and add up to −1. Those numbers are −7 and 6, so we can write (w−7)(w+6)=0.
Find Width: Setting each factor equal to zero gives us w−7=0 or w+6=0. Solving for w gives us w=7 or w=−6. Since a width can't be negative, we discard w=−6.
Find Length: Now that we have the width w=7, we can find the length by substituting w into l=w−1. So l=7−1=6.
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