addition and division
to solve, we need to get X by itself on one side. since we have 3 numbers, 2x, -4, and 16, we can add -4 to 16 but not 2x because we dont know what 2x is.
so, we have to do an inverse operation.
add 4 to both sides
2x=20
then, since x is attached by multiplication we need to divide by 2 to get x by itself
20 divided by 2 is 10
x = 10
