5x to the second power+4+6y-1+3y-4x to the second power-5

Combine like terms

The like terms in the expression are 5x^2 and -4x^2.

Combining these terms, we get 5x^2 - 4x^2 = x^2.

The like terms in the expression are 6y and 3y.
Combining these terms, we get 6y + 3y = 9y.

The simplified expression is x^2 + 9y - 2.

To combine like terms, let's group them together:

5x^2 - 4x^2 + 4 + (-1) - 5 + 6y + 3y

Combining the x^2 terms:

(5x^2 - 4x^2) + 4 + (-1) - 5 + 6y + 3y

Simplifying:

x^2 + 4 + (-1) - 5 + 6y + 3y

Combining the constant terms:

(x^2) + (4 - 1 - 5) + (6y + 3y)

Simplifying:

x^2 + (-2) + (9y)

The final expression after combining like terms is:

x^2 - 2 + 9y