How do you factor 16r^2 - 25a^2 ?

2 Answers
Apr 25, 2018

16r^2-25a^2=color(blue)((4r+5a)(4r-5a))

Explanation:

Remember: (x^2-y^2) can be factored as (x+y)(x-y)

Using 16r^2 as x^2 (that is using 4r as x), and
using 25a^2 as y^2 (that is using 5a as y)

we get
color(white)("XXX")(4r+5a)(4r-5a)

Apr 25, 2018

(4r-5a)(4r+5a)

Explanation:

16r^2-25a^2" is a "color(blue)"difference of squares"

"which factors in general as"

•color(white)(x)a^2-b^2=(a-b)(a+b)

"here "16r^2=(4r)^2" and "25a^2=(5a)^2

rArra=4r" and "b=5a

rArr16r^2-25a^2=(4r-5a)(4r+5a)