Answer
-2x$^6$+x$^4$-3x$^2$
Work Step by Step
Distribute the negative sign to the parentheses and then combine like terms.
(-3x$^6$+3x$^4$-x$^2$)-(-x$^6$+2x$^4$+2x$^2$)
-3x$^6$+3x$^4$-x$^2$+x$^6$-2x$^4$-2x$^2$
(-3x$^6$+x$^6$)+(3x$^4$-2x$^4$)+(-x$^2$-2x$^2$)
-2x$^6$+x$^4$-3x$^2$