Depends on what you're trying to do here.
If you need simplification:
Replace all + or - with a - sign. Adding a negative is the same as subtracting. So you would have:
(2x+3)(x+5)-2x(x-4)
Then you simplify each term by the FOIL method. You get:
2x^2+13x+15+(-2x^2+8x)
Adding the terms together will get you:
21x+15
This is your final answer.
Extra Information:
FOIL Method: Distributes Binomials. The letters stand for First, Outer, Inner, Last.
First = Multiply terms first occurring in binomial.
Outer = Multiply outermost terms in the product
Inner = Multiply innermost terms
Last = Multiply the terms occurring last.
