Question

Solve the system of equations.

Answer 1

Answer:

Option b. (x = 3, y = 20, z = -14)

Step-by-step explanation:

Given:

2x + 2y + 3z = 4

5x + 3y + 5z = 5

3x + 4y + 6z = 5

Solve using Cramer’s rule

∴ $\left[\begin{array}{ccc}2&2&3\\5&3&5\\3&4&6\end{array}\right] =\left[\begin{array}{ccc}4\\5\\5\end{array}\right]$

∴A = $\left[\begin{array}{ccc}2&2&3\\5&3&5\\3&4&6\end{array}\right] = -1$

Ax = $\left[\begin{array}{ccc}4&2&3\\5&3&5\\5&4&6\end{array}\right] = -3$

Ay = $\left[\begin{array}{ccc}2&4&3\\5&5&5\\3&5&6\end{array}\right] =-20$

Az = $\left[\begin{array}{ccc}2&2&4\\5&3&5\\3&4&5\end{array}\right] = 14$

∴ x = Ax/A = -3/-1 = 3

   y = Ay/A = -20/-1 = 20

   z = Az/A = 14/-1 = -14

So, the answer is option b. (x = 3, y = 20, z = -14)