You can put this solution on YOUR website! (3x^3+9x^2-2x)-(7x^3-6x^2+1)
I'm going to rewrite it like this -nothing changes:
-(7x^3-6x^2+1)+3x^3+9x^2-2x Parenthesis not needed
-(7x^3-6x^2+1) = -7x^3+6 x^2-1 Parenthesis not needed here either:
-7x^3+6x^2-1+3x^3+9x^2-2x
Now group like terms:
3x^3-7x^3+9x^2+6x^2-2x-1 = (3x^3-7x^3)+(9x^2+6x^2)-2x-1:
(3x^3-7x^3)+(9x^2+6x^2)-2x-1
Let's add like terms on left:
3x^3-7x^3 = -4x^3
So now we have:
-4 x^3+(9x^2+6x^2)-2x-1
Now let's add the other side:
9x^2+6x^2 = 15x^2
Put both together:
-4x^3+15x^2-2x-1
Now I factor -1 out of -4 x^3+15 x^2-2 x-1 to get your answer:
-(4x^3-15x^2+2x+1)
