Chapter 6.5, Problem 27HP

To determine

To find which of the given system is different

Answer to Problem 27HP

Third

Explanation of Solution

Calculation:

Looking at the first, second and the fourth system of equations,

The equations involve x and y separately as linear equations.

But in the third,

  $y=x+1$

  $\Rightarrow -x+y=1$

Also,

  $\begin{array}{l}y=\frac{2}{x}\\ \Rightarrow xy=2\end{array}$

Where the equation in involving two variables together as one which does not form a linear equation.

Conclusion:

Therefore, the third system of equation is different.