Question

Solve the system using substitution AND elimination: -y + z = -9 y - 5z = 29

Please show and explain all steps, thank you for your help.

Answer 1

Y=4, Z= -5

Steps:

-y +z = -9 -------(1)

y -5z = 29 ------(2)

from (1):

z = y-9 ------(3)

Substitute (3) in (2)

y - 5(y - 9) = 29

y - 5y +45 = 29

-4y = 29 -45

-4y = -16

Divide both side by ( -4)

y = 4

Use the value y=4 in (1), (2) or (3).

IN (1):

-(4) +z = -9

z = -9 +4

z = -5