Question

Solve the system of linear equations 1x-2y=-60 and 5x+6y=20

Answer 1

`\displaystyle\\ \left \{ { \cdot3 \atop {5x+6y=20~~~~~~~~~~}} \right\\\\\\ \left \{ {{3x-6y=-180} \atop {5x+6y=20~~~~}} \right\\ \text{- - - - - - - - - - - - - -}\\\\ 8x ~~~~~~/~~~=-160\\\\ 8x=-160\\\\ x= (-160)/(8) =\boxed{-20} \\\\ 5x+6y=20\\\\ 6y = 20 - 5x\\\\ y = (20 - 5x)/(6) = (20 - 5\cdot (-20))/(6)=(20+ 100)/(6)=(120)/(6)=\boxed{20}`