Question

Solve these system of linear equations:

5x-y=10}
4x-2y=20}

AND:

3x+4y=12}
2x-y=-10}

WITH STEPS PLEASE!!!!!

Answer 1

`5x-y=10 \\ 4x-2y=20 \ \ \ |\hbox{divide both sides by (-2)} \\ \\ 5x-y=10 \\ \underline{-2x+y=-10} \ \ \ |\hbox{add by sides} \\ 5x-2x-y+y=10-10 \\ 3x=0 \\ x=0 \\ \\ \hbox{substitute 0 for x in one of the equations:} \\ 5 * 0 -y=10 \\ -y=10 \\ y=-10 \\ \\ \hbox{the answer:} \\ x=0 \\ y=-10`




`3x+4y=12 \\ 2x-y=-10 \ \ \ |\hbox{multiply both sides by 4} \\ \\ 3x+4y=12 \\ \underline{8x-4y=-40} \ \ \ |\hbox{add by sides} \\ 3x+8x+4y-4y=12-40 \\ 11x=-28 \\ x=-(28)/(11) \\ x=-2 (6)/(11) \\ \\ \hbox{substitute -28/11 for x in one of the equations:} \\ 2 * (-(28)/(11))-y=-10 \\ -(56)/(11)-y=-(110)/(11) \\ -y=-(110)/(11)+(56)/(11) \\ -y=-(54)/(11) \\ y=(54)/(11) \\ y=4 (10)/(11) \\ \\ \hbox{the answer:} \\ x=-2(6)/(11) \\ y=4 (10)/(11)`