( )°+4x°=90°

(7x-9)°
4x°

To solve this equation, we need to isolate the variable x.

The equation is: ( )° + 4x° = 90°

If we rewrite the equation without the parentheses, it becomes: 4x° + 7x - 9 = 90°

Combining the like terms, the equation becomes: 11x - 9 = 90°

Next, we can add 9 to both sides of the equation to isolate the variable: 11x = 99°

Now, divide both sides of the equation by 11 to solve for x: x = 9°

Therefore, the solution to the equation is x = 9°.