If 18 is decreased by the sum of a number and 6, the result is 4 less than 3 times the number.

Let's do some coloring:

If 18 is decreased by the sum of a number and 6, the result is 4 less than 3 times the number.

Let's replace the words "a number and the number by x. Then we have:

If 18 is decreased by the sum of x and 6, the result is 4 less than 3 times x.

Let's do some coloring:

If 18 is decreased by the sum of x and 6, the result is 4 less than 3 times x

Next let's replace the words the sum of x and 6 by (x+6) 

If 18 is decreased by (x+6), the result is 4 less than 3 times x.

Let's do some coloring:

If 18 is decreased by (x+6), the result is 4 less than 3 times x.

Next let's replace 3 times x by 3x

If 18 is decreased by (x+6), the result is 4 less than 3x.

Let's do some coloring:

If 18 is decreased by (x+6), the result is 4 less than 3x.


To get 4 less than 3x, we have to start by putting down 3x and then we make
it 4 less by subtracting 4 from it, so we have 3x-4.  So let's replace 4 less than 3x by 3x-4:

If 18 is decreased by (x+6), the result is 3x-4.

Now let's delete some unnecessary words:

If 18 is decreased by (x+6), the result is 3x-4.

And we have the same thing which is:

18 decreased by (x+6) is 3x-4.

Now let's do some coloring:

18 decreased by (x+6) is 3x-4.

The get that, we start with 18 and then to decrease it by (x+6) we
subtract (x+6) from the 18 and get 18-(x+6).  So we have:

18-(x+6) is 3x-4

Now we do some coloring:

18-(x+6) is 3x-4

And replace the word "is" by an equal sign and we end up with the
equation:

18-(x-6) = 3x-4

Can you solve that? If not post again asking how.

Answer: x = 7 

Edwin