Question

у = $-\frac{3}{8}$ х +7,5
Найдите х ,если у=1, у=-1, у= $-\frac{2}{3}$ , у=5

Answer 1

$y=-\frac{3}{8}x+7,5;\\\frac{3}{8}x=7,5-y;\\x=20-\frac{8}{3}y;\\y=1;\ x=20-\frac{8}{3}=17\frac{1}{3};\\y=-1;\ x=20+\frac{8}{3}=22\frac{2}{3};\\y=-\frac{2}{3};\ x=20-\frac{8}{3}(-\frac{2}{3})=18\frac{2}{9};\\y=5;\ x=20-\frac{8}{3}*5=6\frac{2}{3};$