Question

Substitution method

X = 4
2x - 3y = -19

Answer 1

2(4)-3y=-19
8-3y=-19
-3y=-27
y=9

Answer 2

`\left\{\begin{array}{ccc}x=4\\2x-3y=-19\end{array}\right\\\left\{\begin{array}{ccc}x=4\\2\cdot4-3y=-19\end{array}\right\\\left\{\begin{array}{ccc}x=4\\8-3y=-19\end{array}\right\\\left\{\begin{array}{ccc}x=4\\-3y=-19-8\end{array}\right\\\left\{\begin{array}{ccc}x=4\\-3y=-27&/:(-3)\end{array}\right\\\left\{\begin{array}{ccc}x=4\\y=9\end{array}\right`