Question

(x+5)^2 -(x-5)^2=

Simplify.
Help please :)

Answer 1

this is just the difference of two squares, so you have

((x+5)+(x-5))*((x+5)-(x-5))
= (2x)(10)
= 20x

If you expand it all out, you will easily see that everything but the x terms cancel out.