Question

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

Answer 1

Answer:

x + y = 7

3x - y = 1

Adding both the equations

4x = 8

x = 2

substitute x value in any of the 2 equations

x + y = 7

2 + y = 7

y = 5

Answer 2

Given :-

$\longrightarrow \sf x + y = 7 \: ....(1)\\ \\ \longrightarrow \sf 3x - y = 1 \: ....(2)$

To Find :-

• Value of x and y

Solution :-

From equation ( 1 ) we have

$\sf \implies x + y = 7 \\ \\\sf \implies x =7 - y$

Substitute value of x in equation ( 2 )

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

Put value of y in equation equation ( 1 )

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