Simplify the equation x+(x+3y)

2x + 3y

To simplify the equation x + (x + 3y), you can use the distributive property to remove the parentheses:

x + (x + 3y)

First, distribute the x inside the parentheses:

x + x + 3y

Combining like terms, we get:

2x + 3y

So, the simplified form of the equation x + (x + 3y) is 2x + 3y.