1. Create an equation  $$\frac{x+3}{x+4+3}=\frac{4}{5}$$ 
2. Solve for x, multiply by x+4+3 to remove x from the denominator  $$x+3\ =\ \frac{4\left(x+4+3\right)}{5}$$ 
3. Multiply by 5 to remove 5 from the denominator  $$5\cdot\left(x+3\right)=4x+28$$ 
4. Simplify by moving all x terns to the same side of the equation  $$5x-4x=28-3$$ 
5. x=25
6. Enter in the value of x for the original equation of  $$\frac{x}{x+4}=\frac{25}{25+4}=\frac{25}{29}$$ 

 $$\frac{25}{29}$$