11. Six times a certain number less 31 is the same as 10 subtracted from Ehree times the number. Write the equation and find the number.

Step-by-step explanation:

x       - a certain number

6x  -  - six times the number

6x-31    - six times the number less 31

3x        - three times the number

3x-10    -  10 subtracted from  three times the number

so the equation:

6x - 31 = 3x - 10

    +31       +31

 6x  =  3x + 21

 -3x     - 3x

3x  = 21  

 ÷3     ÷3

 x = 7

Check:  6•7-31=42-31=11;   3•7-10=21-10=11  

true

explanation:

7

step-by-step explanation:

the answer would be 7