Question

What is the sum of the three solutions (find the values for x, y, and z, then add the answers)? 2x + 3y − z = 5 x − 3y + 2z = −6 3x + y − 4z = −8 Show All Work !!

Answer 1

x + y + z = 4

Explanation:

Give equations are,

2x + 3y - z = 5 --------(1)

x - 3y + 2z = -6 --------(2)

3x + y - 4z = -8 --------(3)

By adding equations (1) and (2),

(2x + 3y - z) + (x - 3y + 2z) = 5 - 6

3x + z = -1 -------(4)

By multiplying equation (3) by 3, then by adding to equation (2)

(9x + 3y - 12z) + (x - 3y + 2z) = -24 - 6

10x - 10z = -30

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

By adding equation (4) and (5),

(3x + z) + (x - z) = -1 - 3

4x = -4

x = -1

From equation (5),

-1 - z = -3

z = 2

From equation (1),

2(-1) + 3y - 2 = 5

-2 + 3y - 2 = 5

3y = 5 + 4

y = 3

Therefore, x + y + z = -1 + 3 + 2

x + y + z = 4