/-знак для дроби 2\3*x=4\9*(75-x) срооочно
2/3*х=4/9*(75-х) 2/3х=100/3-4/9х 2/3х+4/9х=100/3 6/9х+4/9х=100/3 10/9х=100/3 х=100/3:10/9 100/3:10/9=100/3*9/10=30 x=30