Algebra 2
posted by Sira .
What would be the simplest way to eliminate one of the variables? Below is a system of three equations in three variables:
1. x+y+3z=7
2. 2x4y+z=7
3. 3x+5y4z=6

one simple way is to substitute x #1 into #2 and #3:
2(7y3z)  4y + z = 7
3(7y3z) + 5y  4z = 6
which gives you
6y 5z = 7
2y  13z = 27
now we see 2y = 13z27, so
3(13z27)  5z = 7
44z = 88
z = 2
so, y = (2627)/2 = 1/2
and x = 7(1/2)6 = 1/2