Question 955929
D=David's age; B=brother's age=D+3
D+B=17 Since B=D+3, it follows:
D+(D+3)=17 Subtract 3 from each side.
2D=14 Divide each side by 2
D=7 ANSWER 1: David is 7 years old.
B=D+3=7+3=10 ANSWER 2:David's brother is 10 years old.
CHECK:
D+B=17
7+10=17
17=17