Log4(x+3)=log4^3
x+3=4^3
x+3=64
x=61
по моему так
121:у=11 у=121:11 у=11 121:11=11 11=11
Х*6=144*7
Х*6=1008
Х=1008:6
Х=168
Х/7=144/6
Х/7=24
Х=24*7
Х=168
4 5/7 - (х - 6 3/7) = 2 19/30
х - 6 3/7 = 4 5/7 - 2 19/30
х - 6 3/7 = 2 17/210
х = 2 17/ 210 + 6 3/7
х = 8 107/210