Q. 24 - Precalculus Enhanced with Graphing Utilities

Question

In Problems 15 – 42, solve each system of equations using Cramer’s Rule if it is applicable. If Cramer’s Rule is not applicable, say so. 

$\left\{\begin{array}{l}-x+2y=5\\ 4x-8y=6\end{array}\right.$

Step-by-Step Solution

Answer

For the given system of equations Cramer's rule is not applicable because $D=0.$

Step 1. Given Information

The given system of equation is

$\left\{\begin{array}{l}-x+2y=5\\ 4x-8y=6\end{array}\right.$

We have to solve the system of equations using Cramer's rule if it is applicable.

Step 2. Finding the determinant

The determinant D of the coefficients of the variables is

$$\begin{gathered} D=\left|\begin{array}{cc}-1& 2\\ 4& -8\end{array}\right| \\ D=\left(-1\right)\left(-8\right)-\left(2\right)\left(4\right) \\ D=\left(8\right)-\left(8\right) \\ D=0 \end{gathered}$$

Since $D=0$ Cramer's rule is not applicable.