Question

Multiply (2x+5y)(2x-5y)

Answer 1

\[(a + b)(c + d) = ac + ad + bc + bd\]
can you solve now?

Answer 2

u could use the rule
(a+b)(a-b)=a^2-b^2

Answer 3

(2x + 5y)(2x - 5y)
use the foil method....(first, outside, inside, last)
First : (2x)(2x) = 4x^2
Outside : (2x)(-5y) = -10xy
Inside : (5y)(2x) = 10xy
Last : (5y)(-5y) = - 25y^2

now we have ...
4x^2 - 10xy + 10xy + (-25y^2)
4x^2 - 25y^2

I think that is how to do this problem