Answer:
1st number: 20
2nd number: 25
3rd number: 75
Step-by-step explanation:
x + y + z = 120
x = y - 5
z = 3y
plug that in!
(y-5) + y + (3y) = 120
remove the parenthesis (I used them to show you what I was replacing), and add like terms.
5y - 5 = 120
move -5 to the other side
5y = 120 + 5
5y = 125
divide both sides by 5
y = 25
now that you have one number, use the equations from before to solve for the rest!
x = (25) - 5
z = 3(25)
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x = 20
y = 25
z = 75
