In algebra special products and the questions says to factor the equation 200x^2-18 and I don't get how to.

factor out a two, then what remains will be the difference between two perfect squares.

I got as far as this 2(100x-3)^2 and that isn't right becaus ethe 18 has to be negative.

2(100x^2-9)
Now, what is (10x-3)(10x+3) ?

Review the factors for a difference of two squares (a^2-b^2).