Question

X + 5y -18z= -35

y -4z= -8
Find the solution that corresponds to z=1. (3 parts to the
question)
1) x=___, y=___, and z=1 2) x=___, y=___, and z=1 3) x=___,
y=___, and z=1

Answer 1

1) x = -35 - 5y + 18z

y = -8 + 4z

z = 1

2) x = -17 - 5y

y = -4

z = 1

3) x = 3

y = -4

z = 1

Explanation:

x + 5y - 18z = -35

y - 4z = -8

• Make x and y the subjects of their own equations.

x = -35 - 5y + 18z

y = -8 + 4z

• Substitute z for 1.

x = -35 - 5y + 18(1)

x = -35 - 5y + 18

x = -35 - 5y + 18

x = -17 - 5y

y = -8 + 4(1)

y = -8 + 4

y = -4

• Substitute y for -4.

x = -17 - 5(-4)

x = -17 + 20

x = 3