When you solve a proportion, your first step should be to cross-multiply.
[tex] \frac{2x}{5} [/tex] = [tex] \frac{x + 3}{3} [/tex]
When you cross-multiply, you should get this equation:
(2x)(3) = (x + 3)(5)
Now, solve it using algebra.
(2x)(3) = (x + 3)(5) Multiply
6x = 5x + 15 Subtract 5x from both sides
x = 15
The value of x is 15.
