SOLUTION: use the echelon method to solve. x + y/3 = -6 x/5 + y/4 = -7/4

Algebra ->  Linear-equations -> SOLUTION: use the echelon method to solve. x + y/3 = -6 x/5 + y/4 = -7/4      Log On


   

Question 147753This question is from textbook
: use the echelon method to solve.
x + y/3 = -6
x/5 + y/4 = -7/4 This question is from textbook

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
1.x%2By%2F3=-6
2.x%2F5%2By%2F4=-7%2F4
or in matrix form,

Multiply eq. 1 by (-1/5) and add to eq. 2, to remove x.
%28-1%2F5%29x-y%2F15=6%2F5
x%2F5%2By%2F4=-7%2F4
2'.%28-1%2F15%2B1%2F4%29y=6%2F5-7%2F4
2'.%2811%2F60%29y=-11%2F20
Now your two equations, in echelon form, are
1.x%2By%2F3=-6
2'.0x%2B%2811%2F60%29y=-11%2F20
or in matrix form,

You can solve for y from 2'.
2'.%2811%2F60%29y=-11%2F20
y=-%2811%2F20%29%2860%2F11%29
y=-3
From 1,
1.x%2By%2F3=-6
x=-6%2B3%2F3
x=-6%2B1
x=-5