I can't get this problem, could you please help me?
Solve each system of equations
x+2y=12
3y-4z=25
x+6y+z=20
Rewrite one of the equations and plug into another equation and solve for each variable:
(x + 2y = 12) = (x = 12-2y)
plug x in (x+6y+z=20) = (12-2y+6y+z =20) is equal to (4y+z=8) rewrite (4y+z=8) and you get (z=8-4y). plug z in (3y-4z=25) solve and you get y=3. now you have all three variables. plug into each equation and solve for missing variable.
y=3
z=-4
x=6