Simplify the algebraic expression by combining the like (or similar) terms.
−2x + a2 − 3 + 4a2 + 5x + 5

Hello! So any number that has the same exponent (in this case to the power of 2) can be combined. Similarly, any number that has the same variable (in this case x) can also be combined. Finally, your basic numerals can be added and subtracted like you normally would (in this case -3 and 5). 

When you combine all the similar numbers, the equation simplifies to 5a² + 3x+2.

Just a hint, I have found it is easier to first rewrite the equation so that any subtraction is rewritten as adding a negative number. So in this case, -2x + a² + (-3) + 4a² + 5x +5.

Also a² is the same as 1a². So a² + 4a² can be rewritten as 5a².

Good luck!