One less than 8 times a number is the same as the number plus 13

8n-1= 13+n is the equation, n=2 is the answer for the variable.

Step-by-step explanation:

8n-1= 13+n

Move the variable to one side.

8n-1= 13+n

-1n         -1n

7n-1= 13

Now, add to both sides, since that is the opposite of subtracting.

7n-1= 13

   +1  +1

Then, divide to both sides by 7 to leave the variable by itself.

7n= 14

7     7

n= 2

the answer is 62.8 cubic units