SOLUTION: I'm having trouble on how to figure this out. I don't know how to set this up as an equation. the sum of three numbers is 137. The second number is 30 less than 4 times the first.

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Question 209599: I'm having trouble on how to figure this out. I don't know how to set this up as an equation. the sum of three numbers is 137. The second number is 30 less than 4 times the first. The third number is 20 more than twice the first number. please help me figure out how to write this as an equation! thank you!
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
three numbers, x, y, z
:
Write an equation for each statement:
:
" the sum of three numbers is 137."
x + y + z = 137
:
" The second number is 30 less than 4 times the first."
y = 4x - 30
:
" The third number is 20 more than twice the first number.
z = 2x + 20
:
Using the 1st equation (sum) substitute: (4x-30) for y, and (2x+20) for z
x + (4x-30) + (2x+20) = 137
:
7x - 10 = 137
:
7x = 137 + 10
:
7x = 147
x = 147%2F7
x = 21
:
You should be able to find y and z, check your solutions in the sum equation
If not, email me: ankor@att.net