Solve the system below. Parameterize the solution set. \[ \begin{aligned}-x+2 y+5 z & =11 \\ -2 x+5 y+15 z & =25 \\ 3 x-3 y & =-24\end{aligned} \]
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To solve the system of equations, we start by rewriting the system for clarity: 1. \(-x + 2y + 5z = 11\) \quad (Equation 1) 2. \(-2x + 5y + 15z = 25\) \quad (Equation 2) 3. \(3x - 3y = -24\) \quad (Equation 3) Now, let's simplify Equation (3): \[ 3x - 3y = -24 \implies x - y = -8 \implies x = y - 8. \quad (Equation 4) \] Next, we substitute Equation (4) \(x = y - 8\) into Equations (1) and (2). Substituting into Equation (1): \[ - (y - 8) + 2y + 5z = 11 \] \[ - y + 8 + 2y + 5z = 11 \implies y + 5z + 8 = 11 \implies y + 5z = 3. \quad (Equation 5) \] Substituting into Equation (2): \[ -2(y - 8) + 5y + 15z = 25 \] \[ -2y + 16 + 5y + 15z = 25 \implies 3y + 15z + 16 = 25 \implies 3y + 15z = 9. \] Dividing everything by 3 gives: \[ y + 5z = 3. \quad (Equation 6) \] Now we have two equations, Equation (5) and Equation (6), that are identical. This tells us that \(y + 5z = 3\) can be our main equation. From Equation (5), we can express \(y\) in terms of \(z\): \[ y = 3 - 5z. \] Now substituting back into Equation (4) to find \(x\): \[ x = (3 - 5z) - 8 = -5z - 5. \] Now, our variable \(z\) can be free. Let’s parameterize the solutions in terms of \(z\): - Let \(z = t\), where \(t\) is any real number. Then, we can write: \[ \begin{aligned} x &= -5t - 5, \\ y &= 3 - 5t, \\ z &= t. \end{aligned} \] Therefore, the parameterized solution set is: \[ (x, y, z) = (-5t - 5, 3 - 5t, t) \quad \text{for } t \in \mathbb{R}. \]