How do you factor #64-y^2#?

1 Answer
Jun 18, 2015

Answer:

Here's the result: #(8-y)(8+y)#

Explanation:

Start off by appreciating the fact that: #(a-b)(a+b)=a^2+color(red)(ab-ab)-b^2#
#=>(a-b)(a+b)= a^2-b^2#

So, generally #a^2-b^2 = (sqrt(a^2)-sqrt(b^2))(sqrt(a^2)+sqrt(b^2))#

Therefore, in our present situation,
#(64-y^2)# by comparing with the above results,
#64-y^2= = (sqrt(64)-sqrt(y^2))(sqrt(64)+sqrt(y^2))=(8-y)(8+y)#

That's it!