Step 1 :

Joaquin is 4 years older than Becky .

Let Joaquin age is .

So the age of Becky is .

3 times the sum of their ages is 114. \ \

sum of the ages of Joaquin and Becky is : .

Step 2 :

3 times the sum of their ages is : .

Expand the expression using distributive law.

Distributive law : .

.

Add 12 to each side.

 \
Divide each side by 6. \
 \

So the age of Joaquin is 21 years.

Solution :

The age of Joaquin is 21 years.