Home » » Solve for x and y $$\begin{pmatrix} 1 & 1 \\ 3 & y \end{pmatrix}$$$$\begin{pmatrix} x \\ 1 \end{pmatrix}$$ = $$\begin{pmatrix} 4 \\ 1\end{pmatrix}$$...

# Solve for x and y $$\begin{pmatrix} 1 & 1 \\ 3 & y \end{pmatrix}$$$$\begin{pmatrix} x \\ 1 \end{pmatrix}$$ = $$\begin{pmatrix} 4 \\ 1\end{pmatrix}$$...

### Question

Solve for x and y $$\begin{pmatrix} 1 & 1 \\ 3 & y \end{pmatrix}$$$$\begin{pmatrix} x \\ 1 \end{pmatrix}$$ = $$\begin{pmatrix} 4 \\ 1\end{pmatrix}$$

A) x = 3, y = 8

B) x = 3, y = -8

C) x = -8, y = 3

D) x = 8, y = -3

### Explanation:

$$\begin{pmatrix} 1 & 1 \\ 3 & y \end{pmatrix}$$$$\begin{pmatrix} x \\ 1 \end{pmatrix}$$ = $$\begin{pmatrix} 4 \\ 1\end{pmatrix}$$ = x + 1 = 4
x = 4 - 1
= 3
3x + y =1
3(3) = y = 1
= 9 + y = 1
y = 1 - 9
= -8

## Dicussion (1)

• $$\begin{pmatrix} 1 & 1 \\ 3 & y \end{pmatrix}$$$$\begin{pmatrix} x \\ 1 \end{pmatrix}$$ = $$\begin{pmatrix} 4 \\ 1\end{pmatrix}$$ = x + 1 = 4
x = 4 - 1
= 3
3x + y =1
3(3) = y = 1
= 9 + y = 1
y = 1 - 9
= -8