How do you factor 5y^2-26y+5?

1 Answer
May 28, 2015

Use a version of the AC method...

A=5, B=26, C=5.

AC=5xx5 = 25

since the sign of the constant term is +, look for a pair of factors of AC = 25 which add to give 26. 1 and 25 work.

Use this pair to split the middle term into two, then factor by grouping...

5y^2 - 26y + 5 = 5y^2 - 25y - y + 5

= (5y^2-25y)-(y-5)

= 5y(y-5) - (y-5)

= (5y-1)(y-5)