Answer: Hello there! 
If W is the age of Wilma, J the age of Jamal and T the age of Tim, we get: 
W = 2J 
J - T = 3 
J + W + T = 17 
And we want to find the age of Jamal. 
First, we could replace W using the first equation, and T using the second equation. 
By the first equation, we know that W = 2J and whit the second equation we have that T = J + 3, now we can replace this in the third equation and isolate J. 
J + W + T = 17 
J + 2J + J + 3 = 17 
4J = 17 - 3 
J = 14/4 = 3.5 
So Jamal has 3.5 years. 
Second question: 
the sum of two consecutive integers is 183. what is the smaller integer? 
two consecutive numbers can be written as N and (N + 1) 
then: 
 N + (N+1) = 183 
2N + 1 = 183 
2N = 183 - 1 = 182 
N = 182/2 = 91