Odpowiedź :
x+y = 15
2x + ⅔y = 15 + 7
x+y = 15
2x + ⅔y = 22
x = 15 - y
2x + ⅔y = 22
2(15 - y) + ⅔y = 22
30 - 2y + ⅔y = 22
-1⅓y = 22 - 30
-1⅓y = -8
y = 6
x+ 6 = 15
x = 15-6
x= 9
y=6
x=9
2x + ⅔y = 15 + 7
x+y = 15
2x + ⅔y = 22
x = 15 - y
2x + ⅔y = 22
2(15 - y) + ⅔y = 22
30 - 2y + ⅔y = 22
-1⅓y = 22 - 30
-1⅓y = -8
y = 6
x+ 6 = 15
x = 15-6
x= 9
y=6
x=9