Answer:
Let the missing number be a.
Given that:
[tex](10x-4x^2)-(7x+a) = 3x-6x^2[/tex]
Remove the parenthesis we have;
[tex]10x-4x^2-7x-a= 3x-6x^2[/tex]
Combine like terms we have;
[tex]3x-4x^2-a= 3x-6x^2[/tex]
Subtract 3x from both sides we have;
[tex]-4x^2-a=-6x^2[/tex]
Add [tex]4x^2[/tex] to both sides we have;
[tex]-a=-6x^2+4x^2[/tex]
Simplify:
[tex]-a=-2x^2[/tex]
Divide both sides by -1 we have;
[tex]a=2x^2[/tex]
Therefore, the missing term is, [tex]2x^2[/tex]
