(pls help) algebra
posted by david on .
4x+y-32=1, 6x-y-4z=7, 10x+2y-6z=5 pls show me how to solve for x,y,z. Ans:xx=1.5,y=-2,z=1
here are several ways to do this (as I'm sure your textbook will show - read it, and do web searches for alternate presentations).
(1) 4x+y-3z = 1
(2) 6x-y-4z = 7
(3) 10x+2y-6z = 5
From (1) we see that y = -4x+3z+1, so plug that into (2) and (3):
6x - (-4x+3z+1) - 3z = 7
10x + 2(-4x+3z+1) - 6z = 5
(4) 10x -6z = 8
(5) 2x = 3
From (5) we see x = 3/2
Plug that into (4) and z = 1
Plug x and z into any of the original equations and y = -2
Besides substitution, there's elimination, determinants, matrices, and other methods.
Extra credit: find and fix my typo.