Question

Solve the system of equations using matrices. x+7y=02x−8y=22 Question 7 (Mandatory) (1 point) Step 1. Find the coefficient matrix. A=[blank 1blank 3blank 2blank 4]

Answer 1

x=7

y =-1

Explanation:

Given is a system of equations in x and y as

`x+7y=0\\2x-8y =22`

This can be written in matrix form as

Ax = B

`\left[\begin{array}{ccc}1&7\\2&-8\end{array}\right]\left[\begin{array}{ccc}x\\y\end{array}\right]  =\left[\begin{array}{ccc}0\\22\end{array}\right]`

Let us find inverse of A

`|A| = -8-14 =-22`

`A^(-1) =(-1)/(22) *\left[\begin{array}{ccc}-8&-7\\-2&1\end{array}\right]`

X= A ^(-1) B

x=7, y =-1