48.6k views
5 votes
The sum of three numbers is 75. the third number is 2 times the first. the first number is 5 more than the second. what are the numbers?

User Avck
by
7.8k points

1 Answer

6 votes
x= second number
x+5= first number
2(x+5)= third number


SOLVE FOR SECOND NUMBER
x + (x+5) + 2(x+5)= 75
multiply 2 by its parentheses

x + (x+5) + (2*x) + (2*5)= 75

x + (x+5) + 2x + 10= 75
combine like terms

4x + 15= 75
subtract 15 from both sides

4x= 60
divide both sides by 4

x= 15 second number


FIRST NUMBER
x + 5= 15 + 5= 20

THIRD NUMBER
2(x+5)= 2(15 + 5)= 2(20)= 40

CHECK
15 + 20 + 40= 75
15 + 60= 75
75= 75


ANSWER: The three numbers are 15, 20, 40

Hope this helps! :)
User Marc Zampetti
by
8.0k points

No related questions found