Question

Solve the system of equations by substitution.

x - 3y + 2z = 20
x - 2y - z = 6
Z = 4

Answer 1

x = 6, y = - 2, z = 4

Explanation:

Substitution:

A) x - 3y + 2(4) = 20

x - 3y +8 = 20

x - 3y = 20-8

x - 3y = 12

B) x - 2y - 4 = 6

x -2y = 6 + 4

x - 2y = 10

A) -1(x - 3y = 12) = -x + 3y = 12

(-x + 3y = -12) + (x - 2y = 10)

= y = -2

B) x - 2(-2) = 10

x +4 = 10

x = 10-4

x = 6