Chapter 6.2, Problem 1LC

To determine

To find:The solution of the system

  $\begin{array}{l}4y=x\\ 3x-y=70\end{array}$

Answer to Problem 1LC

  $x=29\frac{1}{11},y=6\frac{4}{11}$

Explanation of Solution

Given information:The system of equation

  $\begin{array}{l}4y=x\\ 3x-y=70\end{array}$

Calculation:

Substituting the value of x from the first equation into the second equation,

  $\begin{array}{l}3x-y=70\\ \Rightarrow 3(4y)-y=70\\ \Rightarrow 12y-y=70\\ \Rightarrow 11y=70\\ \Rightarrow y=\frac{70}{11}\\ \Rightarrow y=6\frac{4}{11}\end{array}$

Substituting the value of y in the first equation,

  $\begin{array}{l}4y=x\\ \Rightarrow 4\cdot \frac{70}{11}=x\\ \Rightarrow x=\frac{320}{11}\\ \Rightarrow x=29\frac{1}{11}\end{array}$

Thus, the solution is $x=29\frac{1}{11},y=6\frac{4}{11}$