To add (2x^2+5xy)+(4x-7xy)-2x^2.

To do the operation of adding , we open the brackets and then bring the like terms together and add the like terms.

2x^2+5xy +4x-7xy -2x^2.

The first term 2x^2 and the 5th term -2x^2 are like terms.

The second term 5xy and the 4th term -7xy are like terms. So collecting the like terms together we get:

(2x^2 -2x^2) + (5xy-7xy) +4x

= 0 - 2xy +4x

= -2xy+4x

= 4x-2xy.

Therefore (2x^2+5xy)+(4x-7xy)-2x^2 = 4x-2xy.

When we add or subtract polynomials, we have to find the variables and exponents that match.

First, we'll remove the brackets:

2x^2 + 5xy + 4x - 7xy - 2x^2

Now, we'll search for the terms that have matching variables.

We notice that 2x^2 and -2x^2 have the same variables and opposite coefficients, so we'll eliminate the terms.

2x^2 - 2x^2 = 0

Now, we'll combine the terms that have the variables x*y:

5xy - 7xy = -2xy

We notice that the term 4x is alone and we'll add it to the final result.

**The result of adding the polynomials is:**

**(2x^2 + 5xy) + (4x - 7xy) - 2x^2 = 4x - 2xy**