Final answer:
To solve the system of equations x + y + z = 7, x - 8y - z = -29, and 4x - y + z = 8, we can use the elimination method. The solution to the system of equations is x = -1, y = 4, and z = 4.
Step-by-step explanation:
To solve the system of equations x + y + z = 7, x - 8y - z = -29, and 4x - y + z = 8, we can use the elimination method. Here are the steps:
- Add the second and third equations together to eliminate z. This gives us x - 8y - z + 4x - y + z = -29 + 8, which simplifies to 5x - 9y = -21.
- Add the first and second equations together to eliminate z. This gives us x + y + z + x - 8y - z = 7 + (-29), which simplifies to 2x - 7y = -22.
- Now we have a system of two equations: 5x - 9y = -21 and 2x - 7y = -22. We can solve this system using any method such as substitution or elimination.
- Let's use substitution. Solve one equation for one variable and substitute it into the other equation. Let's solve the second equation for x: x = (7y - 22) / 2.
- Substitute this expression for x into the first equation: 5((7y - 22) / 2) - 9y = -21. Simplify this equation to get 35y - 110 - 18y = -42, which simplifies further to 17y = 68.
- Divide both sides of the equation by 17 to solve for y: y = 4.
- Substitute this value of y back into the second equation to solve for x: x = (7(4) - 22) / 2. Simplify this expression to get x = -1.
- Substitute the values of x and y into any of the original equations to solve for z. Let's use the first equation: -1 + 4 + z = 7. Simplify this equation to get z = 4.
The solution to the system of equations is x = -1, y = 4, and z = 4.