1
log(3)135/log(15)3=log(3)135:log(3)3/log(3)15=(log(3)5+3):1/(log(3)5+1)=
=(log(3)5+3)*(log(3)5+1)
log(3)5/log(405)3=log(3)5 :log(3)3/log(3)405=log(3)5:1/(log(3)5+4)=
=log(3)5*(log(3)5+4)
(log(3)5+3)*(log(3)5+1) -log(3)5*(log(3)5+4)=
=log²(3)5+log(3)5+3log(3)5+3-log²(3)5-4log(3)5=3
2
3+log(12)27=3+log(27)/log(3)12=3+3/(2log(3)2+1)=
=(6log(3)2+3+3)/(2log(3)2+1)=6(log(3)2+1)/(2log(3)2+1)
3-log(12)27=3-log(27)/log(3)12=3-3/(2log(3)2+1)=(6log(3)2+3-3)/(2log(3)2+1)
=6log(3)2/(2log(3)2+1)
6(log(3)2+1)/(2log(3)2+1) :6log(3)2/(2log(3)2+1)=
=6(log(3)2+1)/(2log(3)2+1)* (2log(3)2+1)/6log(3)2=6(log(3)2+1)/6log(3)2=
=(log(3)2+1)/log(3)2=
log(6)16=log(3)16/log(3)6=4log(3)2/(log(3)2+1)
(log(3)2+1)/log(3)2*4log(3)2/(log(3)2+1)=4
1/ 10*x+3*2=10x+6
2/ x*4+4*2=4x+8
50-4x-8=10x+6
x=6 4*6+4*2=32 50-32=18 рубль
700-400=300
300*y=2100
y=2100/300
y=7
1)75+10=85(км) скорость второго поезда
2)85*4=340(км) поезда проехали за 4 часа
3)880-340=540(км) расстояние между поездами