Question 49927
I see a few errors in your process.  First of all, I am not sure what made you say  -2(x+5)=4x+10.  When you distribute the -2, you should get -2x-10.  So now we have  -2x-10=30.  Now, we want the terms with x alone on 1 side, so we need to move the 10.  The 10 is being subtracted, so we add 10 to both sides.  So -2x-10+10=30+10, so -2x=40.  Now we need just x, so divide by -2 and x=-20.