Do you multiply when you have an x right after a math number like this: 3x+4x = What would it equal?

3x+4x=7x

Step-by-step explanation:

basically 3x+4x means 3*x+4*x

thus, we can take x out as a common factor of both

x (3+4) = x*7=7x

or

you can sum the variables with the same element (x is our element in here)

thus,

3x+4x=7x

if it would be 3x+4y you cannot sum them since the elements are different (x and y)