Previous Year Questions

We are given the following system of three equations with three unknowns x, y, and z:

X+ 2z=3(Equation 1)

x+2y +3z=5 (Equation 2)

3x-5z =-13 (Equation 3)

From Equation 1:

We can solve forx: x=3-2z

Substitute x = (3 - 2z) into Equations 2 and 3

Substitute into Equation 2:

(3-2z) + 2y +3z=5

3-2z+ 2y+3z=5

3+2y+z=5

2y+z=2

Now, we have

2y=2-z

y=(2-z)/2

Substitute into Equation 3:

3(3 -2z)-5z=-13

9 -6z-5z=-13

9-11z=-13

-11z=-22

z=2

From x=3-2z

expressions for x and y.

Now that we know z = 2, substitute this value into the

x=3-2(2)=3-4=-1

From y=(2-2)/2y=0

The solution to the system of equations is: x=-1, y=0

z=2

The correct answer is option b.