Question

Solve:
x + y = 7
3x - 2y = 11

By using Substituting method.​

Answer 1

$\large\underline{\sf{Solution-}}$

$\sf \longmapsto x + y = 7 \: \: - - - (i)$

$\sf \longmapsto 3x - 2y = 11 \: \: - - - (ii)$

By first equation,

$\sf \longmapsto x + y = 7$

$\sf \longmapsto x = 7 - y$

Now, we can find the original value of y.

$\sf \longmapsto 3x - 2y = 11$

$\sf \longmapsto 3(7 - y) - 2y = 11$

$\sf \longmapsto 21 - 3y - 2y = 11$

$\sf \longmapsto 21 - 5y = 11$

$\sf \longmapsto - 5y = 11 - 21$

$\sf \longmapsto - 5y = - 10$

$\sf \longmapsto y = \dfrac{ - 10}{ - 5}$

$\sf \longmapsto y = 2$

Now, we can find the original value of x.

$\sf \longmapsto x + y = 7$

$\sf \longmapsto x + 2 = 7$

$\sf \longmapsto x = 7 - 2$

$\sf \longmapsto x = 5$

Therefore, the values of x and y are 5 and 2 respectively.