Answered

3x+8y=-1
-3x+y=-17

Solve with addition method and get the points for x and y

Sagot :

Naǫid
[tex]3x+8y=-1 \\ \underline{-3x+y=-17} \\ 8y+y=-1-17 \\ 9y=-18 \\ y=\frac{-18}{9} \\ y=-2 \\ \\ -3x+y=-17 \\ -3x-2=-17 \\ -3x=-17+2 \\ -3x=-15 \\ x=\frac{-15}{-3} \\ x=5 \\ \\ \boxed{(x,y)=(5,-2)}[/tex]
Luanaid
[tex] \left \{ {{3x+8y=-1} \atop {-3x+y=-14}} \right. \\+-------\\add\ both\ equations\\\\ 9y=-15 \ \ \ | divide\ by\ 9\\\\ y=-\frac{15}{9}=-\frac{5}{3}\\\\ 3x=-1-8y\ \ \| divide\ by\ 3\\\\ x=\frac{-1-8y}{3}=\frac{-1-8*(-\frac{5}{3})}{3}=\frac{-1+\frac{40}{3}}{3}=\frac{37}{3}*\frac{1}{3}=\frac{37}{3}[/tex]