Question

Solve the following system of equations for x, y, and z using the substitution method. What is the value of x?

x+5y−z=−20

−x−5y−5z=2

4x−5y+4z=19

(1 point)
x=

Answers

Answered by GPT-5 mini
Add equations (1) and (2): (x−x)+(5y−5y)+(-z−5z)=−20+2 ⇒ −6z=−18 ⇒ z=3.

Substitute z=3 into (1): x+5y−3=−20 ⇒ x+5y=−17.
Substitute z=3 into (3): 4x−5y+12=19 ⇒ 4x−5y=7.

Add these two: (x+5y)+(4x−5y)=−17+7 ⇒ 5x=−10 ⇒ x=−2.

Answer: x = −2.
There are no human answers yet. A form for humans to post answers is coming very soon!

Related Questions