The length and width of a rectangle can be expressed as x+3 and x-8 . If the area of the rectangle is 60 square inches , what is the value of x?
Remember that
the area of rectangle is
A=L*W
we have
L=x+3
W=x-8
substitute
A=(x+3)(x-8)
A=60 in2
so
60=(x+3)(x-8)
solve for x
x^2-8x+3x-24=60
x^2-5x-24-60=0
x^2-5x-84=0
solve the quadratic equation using the formula
we have
a=1
b=-5
c=-84
substitute
[tex]x=\frac{-(-5)\pm\sqrt[\square]{-5^2-4(1)(-84)}}{2(1)}[/tex][tex]\begin{gathered} x=\frac{5\pm\sqrt[\square]{361}}{2} \\ \\ x=\frac{5\pm19}{2} \end{gathered}[/tex]the solutions are
x=12 and x=-7 (is not a solution)
therefore
