Question 726685
Equation 1: {{{r + s = 5}}}
Equation 2: {{{3s + 2t = -1}}}
Equation 3: {{{4r + t = 14}}}

Solve for s in (1):
{{{s = 5 - r}}}

Solve for t in (2):
{{{3(5 - r) + 2t = -1}}}
{{{15 - 3r + 2t = -1}}}
{{{2t = 3r - 16}}}
{{{t = (3r - 16)/2}}}

Solve for r in (3):
{{{4r + (3r - 16)/2 = 14}}}
{{{4r + (3/2)r - 8 = 14}}}
{{{(11/2)r = 22}}}
{{{(11/2)r = 22}}}
{{{r = 4}}}

Sub r=4 in (1)
{{{4 + s = 5}}}
{{{s = 1}}}

Sub s=1 in (2)
{{{3(1) + 2t = -1}}}
{{{2t = -4}}}
{{{t = -2}}}

So, r=4, s=1, t=-2