Question

How do you factor `4m ^ { 2} - 36m + 81`?

Answer 1

See a solution process below:

Explanation:

This expression is a case of a special form for quadratics:

#color(red)(x)^2 - 2color(red)(x)color(blue)(y) + color(blue)(y)^2 = (color(red)(x) - color(blue)(y))(color(red)(x) - color(blue)(y))#

`4m^2 - 36m + 81 = color(red)(2m)^2 - (2 * color(red)(2m) * color(blue)(9)) + color(blue)(9)^2 =`

`(color(red)(2m) - color(blue)(9))(color(red)(2m) - color(blue)(9)) = (color(red)(2m) - color(blue)(9))^2`