Simplify each expression by combining like terms.
8t²-2t+5t-4
4y³-5y+y³+3y

isn't like any of the other terms because it is being raised to the second power, so you can leave it alone.

-2t + 5t are like terms because they are both coefficients with the variable t. You can combine these to get 3t.

The only term left is -4, so that will remain the same.

Now, you can combine all of these terms to get  + 3t - 4.