(заранее )
(6(x + y) - 5y = x + 8,
10x - 7(y – x) = -y + 46;

497 - 31(x + y) = 14 - 27x,
13(x - y) + 14 y = 12 x + 13.​

{6x-5y=43 {x=(43+5y)/6 {x=(43+5y)/6 {x=(43+5y)/6

{4x+3y=73 {4*(43+5y)/6+3y=73 {(86+10y)+9y=219 {19y=133

{x=(43+5y)/6 {x=(43+35)/6=78/6=13

{y=7 {y=7

ответ: x=13

y=7

{5x+10y=54 {x=(54-10y)/5 {x=10.8-2y {x=10.8-2y

{10x+5y=46,5 {10x+5y=46,5 {10(10.8-2y)+5y=46,5 {108+(-20+5)y=46,5

{x=10.8-2y {x=10.8-2y {x=10.8-8.2=2.6

{15y=61.5 {y=4.1 {y=4.1

ответ: x=2.6

y=4,1

{12x-7y=2 {7y=12x-2 {y=(12x-2)/7 {y=(12x-2)/7

{9x+14y=7 {9x+14y=7 {9x+14*(12x-2)/7=7 {9x+24x-4=7

{y=(12x-2)/7 {y=(12x-2)/7 {y=(12/3-2)/7 {y=(4-2)/7 {y=2/7

{33x=11 {x=1/3 {x=1/3 {x=1/3 {x=1/3

ответ: x=1/3

y=2/7