Решите систему уравнений, .) х+у/4 - х-у/ 3 = 10 х+у/8 + х-у /6 = 5

( x + y ) / 4 - ( x - y ) / 3 = 10
( x + y ) / 8 + ( x - y ) / 6 = 5

x + y = a ; x - y = b
( a / 4 ) - ( b / 3 ) = 10
( a / 8 ) + ( b / 6 ) = 5

3a - 4b = 120
3a + 4b = 120
6a = 240
a = 40
4b = 120 - 120
b = 0

x + y = 40
x - y = 0
2x = 40
x = 20
y = 40 - x
y = 20
ОТВЕТ ( 20 ; 20 )
Проверка
( 20 + 20 ) / 4 - ( 20 - 20 ) / 3 = 10
( 20 + 20 ) / 8 + ( 20 - 20 ) / 6 = 5

( 40 / 4 ) - 0 = 10
( 40 / 8 ) + 0 = 5

10 = 10
5 = 5

{(х+у)/4-(х-у)/3 =10/*12⇒3x+3y-4x+4y=120⇒-x+7y=120
{(х+у)/8+( х-у)/6 =5/*24⇒3x+3y+4x-4y=120⇒7x-y=120/*7⇒49x-7y=840
прибавим
48x=960
x=960:48
x=20
7*20-y=120
y=140-120
y=20
ответ (20;20)