Given expression is [tex]-3x^2-6x^4+7x^2[/tex].
Now question says to simplify that.
To simplify, we can begin by combining like terms.
Like terms are those terms which contains same variable with equal exponent.
Here [tex]-3x^2[/tex] and [tex]+7x^2[/tex] contains same variable "x" with equal exponent "2". So that means they are like terms and we are allowed to combine their coefficients -3 and +7 which is -3+7=+4.
So the new expression will be
[tex]-6x^4+4x^2[/tex]
Now there are no more like terms that can be combined.
Hence final answer is [tex]-6x^4+4x^2[/tex]
