Let #f(x)=x+8# and #g(x)=2x^2-128#, how do you find #h(x)=(g(x))/(f(x))#?

1 Answer
Dec 21, 2017

#2x-16#

Explanation:

#(g(x))/(f(x))#

#=(2x^2-128)/(x+8)#

#"factorise the numerator"#

#2(x^2-64)larrcolor(blue)"common factor of 2"#

#x^2-64" is a "color(blue)"difference of squares"#

#•color(white)(x)a^2-b^2=(a-b)(a+b)#

#"here "a=x" and "b=8#

#rArrx^2-64=(x-8)(x+8)#

#rArr(2cancel((x+8))(x-8))/cancel((x+8))#

#rArrh(x)=2(x-8)=2x-16#