Chapter 6, Problem 35SGR

To determine

Tocalculate : To solve the two equations using elimination method.

Answer to Problem 35SGR

The value of x is 5and the value of y is7.

Explanation of Solution

Given information :

Given the two equations:

  $\begin{array}{l}x-y=-2\\ 2x+4y=38\end{array}$

Formula Used:

For elimination method, we multiply both the number with two different constant number the we add or subtract the equations, eliminate anyone first variable and then get the value of second variable. Further we put the value of the second variable in any of the equations and get the value of the first variable.

Calculation:

Equations:

  $x-y=-2$ .........Equation 1

Multiplying Equation 1 by number 2, we get:

  $2x+4y=38$ .........Equation 2

  $\frac{2x+4y}{2}=\frac{38}{2}$

  $\Rightarrow x+2y=19$ .........Equation 3

Subtracting Equation 1from Equation 3, we get:

  $\begin{array}{l}(x+2y)-(x-y)=19-(-2)\\ \Rightarrow x+2y-x+y=19+2\\ \Rightarrow 3y=21\\ \Rightarrow y=\frac{21}{3}\\ \Rightarrow y=7\end{array}$

Putting the value of y into Equation 1, we get:

  $\begin{array}{l}x-7=-2\\ \Rightarrow x=7-2\\ \Rightarrow x=5\end{array}$

So the value of x is 5and the value of y is equal to 7.