How do you evaluate #(2x^{2}+10x-48)\div (8x+64)#?

1 Answer
Dec 14, 2017

#color(blue)((x-3)/4)#

Explanation:

We are given the rational expression

#color(red)[(2x^2+10x-48)/(8x+64)]#

Denominator(DR) = #(8x+64)#

We will consider the Numerator(NR) first

We have

#color(green)[(2x^2+10x-48)# #color(blue)(NR)#

Rewrite this quadratic expression as

#color(green)[2(x^2+5x-24)#

We can factorize #color(green)[(x^2+5x-24)#:

#rArr x^2 - 3x + 8x - 24#

#rArr x(x-3)+ 8(x-3)#

Hence, we get the factors as

#(x-3) (x+8)#

Hence our #color(blue)(NR)# will now become

#color(green)(2(x-3) (x+8))# #color(blue)(Res.1)#

Next we will consider DR

Denominator(DR) = #(8x+64)#

We can factorize #(8x+64)# as

#color(green)(8(x+8))# #color(blue)(Res.2)#

We will write the rational expression as #color(red)((NR)/(DR))# using our intermediate results #color(blue)(Res.1)# and #color(blue)(Res.2)#

#color(green)(2(x-3) (x+8))/color(green)(8(x+8))#

Simplify to get

#color(green)(2(x-3) cancel((x+8)))/color(green)(8 cancel ((x+8))#

#color(green) (rArr (2(x-3) )/color(green)8#

#color(green) (rArr (cancel 2(x-3) )/color(green)(cancel (8) (color(red)4))#

#color(blue)((x-3)/4)# Our final answer

I hope you find this solution useful.