A number is decreased by seven. Then, the new number is multiplied by 3 to get an answer of -9.

What is the original number?

1 answer

Let's call the original number "x".

According to the problem, we first decrease this number by 7:

x - 7

Then, we multiply the result by 3 to get -9:

3(x - 7) = -9

We can simplify this equation by distributing the 3:

3x - 21 = -9

Now, we can add 21 to both sides of the equation to isolate the variable:

3x = 12

Finally, we divide both sides by 3 to solve for x:

x = 4

Therefore, the original number was 4.