Chapter 6.3, Problem 3GP

To determine

To solve the given system of equations using elimination method

Answer to Problem 3GP

G (1.75,-1)

Explanation of Solution

Given:

Equations:

$8b+3c=11$

$8b+7c=7$

Calculation:

Let,

$\begin{array}{l}8b+3c=\mathrm{11.......}(i)\\ 8b+7c=\mathrm{7.......}(ii)\end{array}$

Now, subtract equation ( i ) from equation ( ii ),

$\begin{array}{l}\Rightarrow (8b+7c)-(8b+3c)=7-11\\ \Rightarrow 8b+7c-8b-3c=-4\\ \Rightarrow 4c=-4\\ \Rightarrow c=-1\end{array}$

Now, substitute the value of g in equation ( i ),

$\begin{array}{l}\Rightarrow 8b+3\times (-1)=11\\ \Rightarrow 8b-3=11\\ \Rightarrow b=1.75\end{array}$

Conclusion:

Therefore, the required solution for the given system of equation is $(1.75,-1)$ .