SOLUTION: I am so lost on this lesson. Help please! :) 5r - 4s - 3t = 3 r = 3s + 1 t = s + r

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Question 180219This question is from textbook Algebra 2
: I am so lost on this lesson. Help please! :)
5r - 4s - 3t = 3
r = 3s + 1
t = s + r This question is from textbook Algebra 2

Found 2 solutions by Fombitz, stanbon:
Answer by Fombitz(32388)   (Show Source): You can put this solution on YOUR website!
Substitute and get to an equation with one variable.



You now have an equation only in s.
Now solve for s and go back to find r and t.
Repost if you get stuck or need more help.
Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
5r - 4s - 3t = 3
r = 3s + 1
t = s + r
----------------
You want to have one equation with one variable.
Find a variable that is associated with two others, like "s"
r = 3s+1
t =s + r = s+ 3s+1 = 4s+1
-------------------------------
Now substitute for "r" and for "t" in the 1st equation to get:
5(3s+1) - 4s - 3(4s+1) = 3
Solve for "s".
15s + 5 - 4s - 12s - 3 = 3
-s +2 = 3
-s = 1
s = -1
----------------
Substitute to solve for r and for t:
r = 3s+1 = 3(-1) + 1 = -2
---
t = 4s+1 = 4(-1) + 1 = -3
============================
Final Answer:
s = -1
r = -2
t = -3
==============
Cheers,
Stan H.
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