4x + 6x=30

4x + 6x = 30

Add the like terms (4x + 6x)

10x = 30 

Divide 10 by 10x and 30 to get the ten to the other side so x is on its own.

x = 3

4x+6x=30

10x=30

x=3.

4x+6x=30

10x=30

x=3