1) 7/12x-0,5=1,25
2) 5/6x-4,15=2,1
3) 2,7+2/9y=4,3

спасибо

7/12х=1,25+0,57/12х=1,7512х=7/1,7512х=4х=4/12=1/3--------------------------5/6х - 4,15 = 2,15/6х = 2,1 + 4,155/6х = 6,25х = 6,25 : 5 * 6х = 7,5-------------------------------------2,7 + 2/9y = 4.32/9y = 4,3 - 2,72/9y = 1,6y = 1,6 : 2/9y = 7,2