How do you evaluate #\frac { 5x + 5} { x ^ { 2} + 8x + 7} - \frac { 4x - 2} { x ^ { 2} + 8x + 7}#?
1 Answer
Sep 24, 2017
Explanation:
#"since both fractions have a "color(blue)"common denominator"#
#"we can subtract the numerators"#
#rArr(5x+5-4x-(-2))/(x^2+8x+7)#
#=(x+7)/(x^2+8x+7)#
#"factorising the denominator will allow further simplification"#
#"the factors of + 7 which sum to + 8 are + 1 and + 7"#
#rArrx^2+8x+7=(x+1)(x+7)#
#rArr(cancel((x+7)))/((x+1)cancel((x+7)))#
#=1/(x+1)to(x!=-1)#
