Question

3+6x=21

`3 + 6x = 21`

Answer 1

I'm guessing you have to solve for x. To do that, we must isolate it. So, let's subtract 3 from both sides first:

`6x=18`

And now divide by 6 since that's the opposite of multiplication (6 is being multiplied to x):

`x = (18)/(6) =3`

So, your answer is x = 3.