Question

The difference of a twice a number and 10 is less than 28

Answer 1

2n-10<28
   +10 +10         adding 10 to both sides to get the variable alone
2n<38 
_____               divide both sides by 2 to get n by itself on one side
    2

n<19

Check:

(2(18))-10<28
36-10<28
26<28 .......................IT WORKS!!!