Question

x+y=8 & 2x-y=7 by elimination method​

Answer 1

$\texttt{x + y = 8}... ...(1)\\ \texttt{2x - y = 7} ... ...(2)\\ \\ \\ \: \: \: \: \texttt{adding \: eqn(1) \: and \: (2)} \\ \\ \\ \tt{x + \cancel{ \: \: y \: \: } = 8}\\ \tt{2x - \cancel{ \: \: y \: \: } = 7} \\ \tt3x = 15 \\ \tt x = \dfrac{ \cancel{15}}{ \cancel{ \: 3 \: } } \\ \tt \: x = 5$

Now, x+y=8

$\therefore \: \tt y = 8 - x \\ = 8 - 5 \\ = 3$