Question

Which matrix equation can be used to solve the system? (2x+ 5y = 15 X + 3y = 18

Answer 1

Answer:

option 3

Step-by-step explanation:

$AX = B\\X = A^{-1}B\\\\A = \left[\begin{array}{CC}\\2&5\\1&3\end{array}\right]\\\\\\B =\left[\begin{array}{C}\\15&18\end{array}\right]\\\\\\X =\left[\begin{array}{C}\\x&y\end{array}\right]$

$det A = 1\\\\adj A = \left[\begin{array}{CC}\\3&-5\\-1&2\end{array}\right]$

$A^{-1} = \frac{1}{det A} \times Adj A$

      $= 1 \times \left[\begin{array}{CC}\\3&-5\\-1&2\end{array}\right]\\\\\\= \left[\begin{array}{CC}\\3&-5\\-1&2\end{array}\right]$

Therefore,

      $X = A^{-1}B\\\\\\\left[\begin{array}{C}\\x&y\end{array}\right] = \left[\begin{array}{CC}\\3&-5\\-1&2\end{array}\right]\left[\begin{array}{C}\\15&18\end{array}\right]$

Answer 2

THE CORRECT OPTION IS A where the input data is correct