Question

Given {4x+7y = 4 4x-7y = 4How do I solve it by using the addition method? What is the ordered pair?

Answer 1

Given the system of equations;

`\begin{gathered} 4x+7y=4........equation1 \\ \\ 4x-7y=4...........equation2 \end{gathered}`

Using addition method, add equation 1 and equation 2;

`\begin{gathered} 4x+4x+7y-7y=4+4 \\ \\ 8x=8 \\ \\ x=(8)/(8) \\ \\ x=1 \end{gathered}`

Substitute the value of x in equation1;

`\begin{gathered} 4x+7y=4;x=1 \\ \\ 4(1)+7y=4 \\ \\ 4+7y=4 \\ \\ 7y=4-4 \\ \\ 7y=0 \\ \\ y=(0)/(7) \\ \\ y=0 \end{gathered}`

The ordered pair (x,y), of the solution, is;

`(x,y)=(1,0)`