I'm not doing your math homework, this is to help you learn and pass your test :) I will however show you a trick. ask your self this... "What can i factor out of 4x that i can also factor out of 8, which this would be 4. Now what you do if you divide everything by 4
4x/4 = x
8/4 = 2
so 4(x+2) is 4x+8 fully factored, NOW to check, use the distributive property, Multiply 4 back into x+2
4*x = 4x
4*2 = 8
so 4(x+2) = 4x+8