Question

Solve for x, y, and z

Answer 1

Answer:

The solution is x=1,y=2,z=3

Step-by-step explanation:

The given system of equations is ;\

2x−3y+4z=8...(1)

3x+4y−5z=−4...(2)

4x−5y+6z=12...(3)

Make x the subject in equation (1)

$x=\frac{8+3y-4z}{2}...(4)$

Put equation (4) into equation (2) and (3)

$3(\frac{8+3y-4z}{2})+4y-5z=-4$

Multiply through by;

$3(8+3y-4z)+8y-10z=-8$

Expand;

$24+9y-12z+8y-10z=-8$

Simplify;

$17y-22z=-32...(5)$

Equation (4) in (3)

$4(\frac{8+3y-4z}{2})-5y+6z=12$

$2(8+3y-4z)-5y+6z=12$

$16+6y-8z-5y+6z=12$

$y-2z=-4$

$y=2z-4...(6)$

Put equation (6) into equation (5)

$17(2z-4)-22z=-32$

$34z-68-22z=-32$

$34z-22z=-32+68$

$12z=36$

z=3

Put z=3 into equation (6)

y=2(3)-4=2

Put y=2 and z=3 into equation 4

$x=\frac{8+3(2)-4(3)}{2}=1$

The solution is x=1,y=2,z=3