Question 199013
To solve this you must first set up an equation. three times a number would be written as 3x. increased by 6 means you are adding six to your 3x. The result is telling you the problem equals 21.

3x+6=21

To solve you would first subtract 6 from each side. A possitive 6 minus a negative 6 will cancel out your 6's on the left side. You then do 21-6= 15

Your problem should now look like this:
3x=15

You then divide 3 from both sides. 3x divided by 3 cancells out the 3's so you are left with just x. 15 divided by 3 comes out to be 5. Therefore your answer is #1.

three times a number is increased by 6, the result is 21. The number is 5.