Bob is three years older than twice Karen's age. If Karen is eighteen, how old is Bob?
Bob would be 39 years old.
Let's make b a variable for Bob and k as the variable for Karen.
(Variables are letters in Algebra)
You are given that: 2k+3=B and that K=18
Plug 18 into the K. 2(18)+3=
If 2 x 18 is 36 and you add 3, then Bob is 39.
Hoped this helped! :)