7x-21-2x²+6x+2x²=5

To solve the equation 7x - 21 - 2x² + 6x + 2x² = 5, we can start by combining like terms.

7x - 21 - 2x² + 6x + 2x² = 5

Combine the terms 7x and 6x to get 13x:

13x - 21 - 2x² + 2x² = 5

Combine the like terms -2x² and 2x². They cancel each other out:

13x - 21 = 5

Now, we can isolate the x variable by moving the constant term (-21) to the other side of the equation:

13x = 5 + 21

13x = 26

Finally, we divide both sides of the equation by 13 to solve for x:

x = 26/13

So the solution to the equation is x = 2.