Question

Решить методом подстановки {7x-3y=7
{2y-6x=8

Answer 1

{7x-3y=7
{2y-6x=8

{7x-3y=7
{2y=8-6x

{7x-3y=7
{y=4-3x

7x-3(4-3x)=7
7x-12+9x=7
16x=19
x=1 3/16

y=4-3(1 3/16) = 4-57/16 = 4-3 9/16 = 7/16.