Question

The sum of three numbers is 49. The second number is five less than three times the third number. If the first number is twice the amount of the third number, what is the value of the second number?

Answer 1

(x, y, z) → (18, 22, 9)

Explanation:

sum of three numbers is 49

x + y + z = 49

second number is 5 less than three times the third number

y = 3z - 5

first number is twice amount of third number

x = 2z

set of equations

x + y + z = 49

y = 3z - 5

x = 2z

plug in 2nd and 3rd equation into first

(2z) + (3z - 5) + z = 49

combine like terms

2z + 3z - 5 + z = 49

6z - 5 = 49

add 5 to both sides

6z = 54

divide by 6

z = 9

plug z into 2nd and 3rd equations

y = 3(9) - 5

y = 27 - 5

y = 22

x = 2(9)

x = 18

check:

18 + 22 + 9 = 49

(x, y, z) → (18, 22, 9)