How do you factor #50 + 5a - a^2#?

1 Answer
Jun 30, 2018

#(5+a)(10-a)#

Explanation:

#"using the a-c method to factor the quadratic"#

#"the factors of the product "50xx-1=-50#

#"which sum to "+5" are "+10" and "-5#

#"split the middle term using these factors"#

#50+10a-5a-a^2larrcolor(blue)"factor by grouping"#

#=color(red)(10)(5+a)color(red)(-a)(5+a)#

#"take out the "color(blue)"common factor "(5+a)#

#=(5+a)(color(red)(10-a))#

#50+5a-a^2=(5+a)(10-a)#