the dimensions of a rectangle can be expressed as x+6 and x-2. if the area of the rectangle is 65in^2, find the dimensions of the rectangle.
Question
Answer:
[tex]\bf \textit{area of a rectangle}\\\\
A=length\cdot width\qquad \boxed{A=65~in^2}\qquad 65=(\stackrel{length}{x+6})(\stackrel{width}{x-2})
\\\\\\
65=x^2+4x-12\implies 0=x^2+4x-77
\\\\\\
0=(x+7)(x-11)\implies x=
\begin{cases}
-7\\
\boxed{11}
\end{cases}[/tex]it cannot be -7, because that would give a negative value for either dimension, and a dimension for the rectangle cannot be negative.
so, the dimensions would be (11) + 6 and (11) - 2.
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general
10 months ago
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