6g+8k-9g+2k

Simplifying the given expression:

First, we can add the like terms, i.e. 6g and -9g. These have the same variable (g) and hence can be combined as 6g - 9g = -3g.

Similarly, we can add the like terms 8k and 2k as they have the same variable (k), giving us 10k.

Therefore, 6g + 8k - 9g + 2k simplifies to:

(-3g) + (10k)

or

10k - 3g (in the preferred order of writing)

-4x+6x^2+5x

Arranging the terms in descending order of degree:

6x^2 - 4x + 5x

Now, adding the like terms, we get:

6x^2 + x

Therefore, the simplified form of the expression -4x + 6x^2 + 5x is:

6x^2 + x

a^2+5a-3a^2

Combining the like terms in the given expression:

a^2 + 5a - 3a^2

= (-2a^2) + 5a

= -2a^2 + 5a

Therefore, the simplified form of the expression a^2 + 5a - 3a^2 is:

-2a^2 + 5a