Question

Can someone solve and show steps for
r + s + t = 5
2r - 7s - 3t = 13
1/2 r - 1/3s + 2/3t = -1

Answer 1

Multiply first equation by 2:
2r+2s+2t=10
Subtract second from first:
2r+2s+2t=10
-(2r-7s-3t)=-(13)
-5s-t=-3
Now multiply the third equation by 4:
2r-4/3s+2t=-1
Subtract second from third:
2r-4/3s+2t=-1
-(2r-7s-3t)=-(13)
-25/3s-t=-14
Now take your two new equations and subtract:
25/3s-t=-14
-5s-t=-3
40/3s=-11
s=-33/40
Plug in to find s:
-5s-t=-3
-5s+33/40=-3
153/40=5s
s=153/200
Plug in to find r:
2r+2s+2t=10
2r+2(33/40)+2(153/200)=10
2r=10-318/200
2r=8.41
r=4.205
s=.825
t=.765
I'm pretty sure those numbers are all wrong but this is the idea. I don't have paper to write down and figure this out and its hard to keep track of everything on here, sorry.

Answer 2

Yea its wrong.