3x-7y=17   when x=-3,0,3

Sagot :

[tex]3x-7y=17\\-7y=17-3x\ \ \ \ |:(-7)\\y=-\frac{17}{7}+\frac{3}{7}x\\\\When\ x=-3:\\y=-\frac{17}{7}+\frac{3}{7}\cdot(-3)\\y=-\frac{17}{7}-\frac{9}{7}\\y=-\frac{26}{7}=-3\frac{5}{7}\\\\When\ x=0:\\y=-\frac{17}{7}+\frac{3}{7}\cdot0\\y=-\frac{17}{7}=-2\frac{3}{7}\\\\When\ x=3:\\y=-\frac{17}{7}+\frac{3}{7}\cdot3\\y=-\frac{17}{7}+\frac{9}{7}\\y=-\frac{8}{7}=-1\frac{1}{7}[/tex]