For the equation $x=3$, use equivalence transformations to write an equivalent equation with brackets and the variable $x$ on both sides of the equal sign.

Rupa and George solve this system of equations: $5x+y=8 \mathrm{and} x+3y=10$

Rupa

$5x+y=8 ....[\mathrm{1]}\Rightarrow y=8-5x$

$x+3y=10 ...[\mathrm{2] }$

$x+3(8-5x)=10$

George

$5x+y=8 ...[1]$

$x+3y=10 ...[2]\Rightarrow x=10-3y$

$5(10-3y)+y=8$

Copy and complete their working to find their solutions.

Solve the system of equations $5x+y=27$ and $2x+y=12$ using the elimination method. Check the solution algebraically.