Question

find the solution of the pair of linear equations by graphical method X+y=7. 3x-y=1​

Answer 1

Given :-

$\begin{gathered}\longrightarrow \sf x + y = 7 \: ....(1)\\ \\ \longrightarrow \sf 3x - y = 1 \: ....(2)\end{gathered}$

To Find :-

Value of x and y

Solution :-

From equation ( 1 ) we have

$\begin{gathered}\sf \implies x + y = 7 \\ \\\sf \implies x =7 - y\end{gathered}$

Substitute value of x in equation ( 2 )

$\begin{gathered}\sf \implies 3x - y = 1 \\ \\\sf \implies3(7 - y) - y = 1 \\ \\\sf \implies 21 - 3y - y = 1 \\ \\\sf \implies - 4y = 1 - 21 \\ \\\sf \implies y = \frac{ - 20}{ - 4} \\ \\ \large \implies \underline { \boxed{ \sf \purple{ y = 5 }}}\end{gathered}$

Put value of y in equation equation ( 1 )

$\begin{gathered}\implies \sf x + y = 7 \\ \\\implies \sf x + 5 = 7 \\ \\\implies \sf x = 7 - 5 \\ \\ \large\implies \underline{ \boxed{ \sf \purple{ x = 2}}}\end{gathered}$

Answer 2

$\huge\mathrm{Answer}$

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x = 2

y = 7