Question 14240
First and formost, you need to know your Order of Operatoins
A cool way to remember it is:
Please
Excuse
My
Dear
Aunt
Sally

It stands for:
Paranthases
Exponents
Multiplication
Division
Addition
Subtraction

And so your problem is:
2/5(10x+25)=-10-4(x+3)

You first need to do Distributive Property to get rid of the parenthesis

4x+10 = -10-4x-12
The only thing I did was distribute the 2/5 to the 10x and 25 and the -4 to the x and 3
Then you isolate the X's by moving some things around.

8x=-10-10-12
*Remember when you move things across the equal sign, you MUST switch the sign 
Then just solve

8x=-32
X=-4