Question

Solve the system by finding the determinants and using Cramer's Rule:

2x - y = 4
3x + y = 1

Answer 1

(1, - 2)

Explanation:

2x - y = 4

3x + y = 1

A =
`\left[\begin{array}{cc}2&-1\\3&1\end{array}\right]` = 2(1) - 3( - 1) =2 + 3 = 5

`A_(x)` =
`\left[\begin{array}{cc}4&-1\\1&1\end{array}\right]` = 4(1) - 1(- 1) = 4 + 1 = 5

`A_(y)` =
`\left[\begin{array}{cc}2&4\\3&1\end{array}\right]` = 2(1) - 4(3) = 2 - 12 = - 10

x =
`(A_(x) )/(A)` = 1

y =
`(A_(y) )/(A)` = - 2

(1, - 2)