Question

Which system of linear equations has a solution of (-2,1)?

Answer 1

Step-by-step explanation

the easiest way to solve this is by checking the pair orderer on each system of equations and see it the equation becomes true, so

Step 1

check the solution on each system

a)

`\begin{gathered} 2x+3y=-1 \\ x-y=-3 \end{gathered}`

let

`\begin{gathered} (x,y)\Rightarrow(-2,1) \\ x=-2 \\ y=1 \end{gathered}`

replace

`\begin{gathered} 2x+3y=-1 \\ 2(-2)+3(1)=-1 \\ -4+3=-1 \\ -1=-1\Rightarrow true \end{gathered}`

and

`\begin{gathered} x-y=-3 \\ -2-(1)=-3 \\ -3=-3\Rightarrow true \end{gathered}`

so, A is the solution

Step 2

b)