Question

815=6х9
2/12=15/9х
12/13=18х/39

Answer 1

8/15 = 6x/9
8*9 = 15*6x
72 = 90x
90x = 72
9x = 8
x = 8/9

2/12 = 15/9x
18x = 180
x = 10

12/13 = 18x/39
468 = 234x
234x = 468
x = 2

Answer 2

спасибо огромное

Answer 3

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