Question

Solve the system of equations by elimination.

5x − 2y − z = 15
x + y + 2z = 9
−x − y + 3z = 11

Answer 1

x=3 y=-2 z=4b

Explanation:

5x-2y-z=15

5(-x-y+3z=11)

5x-2y-z=15

-5x-5y+15z=55

-7y+14z=70

-5(x+y+2z=9)

5x-2y-z=15

-5x-5y-10z=-45

5x-2y-z=15

-7y-11z=-30

-7y+14z=70

-1(-7y-11z=-30)

-7y+14z=70

7y+11z=30

25z=100

z=4

-7y+14(4)=70

y=-2

5x-2(-2)-(4)= 15

x=3