Using a cramers and guassian elimination method solve this;
a+2b+3c=600
2a+3b+c= 900
3a+b+2c=800
D = -18
Dx = -3500
Dy = -2900
Dx = -1100
I'll let you do the elimination; come on back if you get stuck, and show where things went south.
a+2b+3c=600
2a+3b+c= 900
3a+b+2c=800
Dx = -3500
Dy = -2900
Dx = -1100
I'll let you do the elimination; come on back if you get stuck, and show where things went south.