Question

The sum of fifteen and six Times an unknown number is eighty one what is the unknown number

Answer 1

Answer:

Let n = the unknown number

 

The sum of 6 times a number and 10 (6n + 10) is equal to the difference of the number and 15 (n - 15)

 

6n + 10 = n - 15

 

5n = -25

 

n = -5

 

Check:

 

6n + 10 = n - 15

6(-5) + 10 = -5 -15

-30 + 10 = -20

-20 = -20