-4x(3x-7y^2+4)

Well, I'll give you an example:

a(b+2c-a)

Using the distributive property, we have = (a x b) + (a x 2c) + (a x -a) = ab + 2ac - a^2

You see what I did? I multiplied each term in brackets by the term outside brackets. Now, do the same, and post your answer. :)