How can I get a better understanding of this immediate algebra class that i'm taking online the professor goes so fast and make so many mistakes that its so confusing to where as I'm not even trying to pass this class I'm ready to give up.

she showed us examples on combine like terms but its was an simple one I stuck on the first one like this

5X - 10X to the 2nd power + 15 - 4X to the 2nd power + 7X - 6 - 10 + 7 x to the 2nd power it says combine like term.so how do i suppose to combine the terms: that's all i know.

5x + 7x

10x2 - 4x2 + 7x2

15- 6 - 10