How do you factor the expression #2x^2-9x-5#?
1 Answer
May 12, 2018
Explanation:
#"using the a-c method to factorise the quadratic"#
#"the factors of the product "2xx-5=-10#
#"which sum to - 9 are - 10 and + 1"#
#"split the middle term using these factors"#
#2x^2-10x+x-5larrcolor(blue)"factor by grouping"#
#=color(red)(2x)(x-5)color(red)(+1)(x-5)#
#"take out the "color(blue)"common factor "(x-5)#
#=(x-5)(color(red)(2x+1))#
#rArr2x^2-9x-5=(x-5)(2x+1)#
