Question

The sum of three numbers is 78. The second number is 10 more than the first, and the third number is two times the second number.

1. Write an equation that will help you determine the 3 numbers.
2. Solve the equation showing all your steps.
3. Tell what the 3 numbers are.

Answer 1

Explanation:

a+b+c=78

b=10+a

c=2b

then, we back the first

a+10+a+2b=78

2a+2b=78- 10

2a+2(10+a)=68

2a+2a=48

4a=48

a=12

b=22

c=44