College Algebra
posted by Eli .
Solve the system:
x + y + z = 1
2x + 2y + 5z = 1
5x + 2y + 3z = 8
what is the value of x in the solution?

By what method are you using. If not your calculator on matricies, then Irecommend the method of determinants.

Use simultaneous equation method:
x=yz1...(1)
Now, the equation 2 become:
2(yz1)+2y+5z=1
2y2z2+2y+5z=1
3z=1+2; z=3
Now equation 1 becomes
x=y31=y4; i.e, x=y4....(a)
equation 3 becomes:
5(y4)+2y+3(3)=8
5y20+2y+9=8
3y=19; y=19/3
Now the very first equation becomes
x+2(19/3)+3=1
x=13+38/3=38/32=12.72=10.7
hence x=10.2