(x+y)=a;(X-y)=b
5а-7b = 10
4a + 3b = 51
5a = 7b + 10 a = 1,4b + 2
4(1,4b + 2) + 3b = 51
5,66 + 8 + 3b = 51
8,66 = 43
b = 5
a = 1,4.5+2= 7+2=9
x+y=9
x-y=5
2x = 14
x=7
y=9-7=2
ответ (7;2)
(x+y)=a;(X-y)=b
5а-7b = 10
4a + 3b = 51
5a = 7b + 10 a = 1,4b + 2
4(1,4b + 2) + 3b = 51
5,66 + 8 + 3b = 51
8,66 = 43
b = 5
a = 1,4.5+2= 7+2=9
x+y=9
x-y=5
2x = 14
x=7
y=9-7=2
ответ (7;2)