120/162*13/60+200/243÷100/81-1/13*10/1=120/162*13/60=120/81*13/30=1560/2430
200/243÷100/81=200/243*81/100=2/3*1/1=2/3
1560/2430+2/3=780/810+1/1=780/810+810/810=1590/810
1/13*10/1=10/13-2/3=30/39-26/39=4/39
(с-863)=39765:1205
С-863=33
С=33+863
С=896
(5020+z)=36054*23
5020+z=829242
Z=829242-5020
Z=824222
1)6+6+4=16см
2)10+4+7=21см
3)4,5+54+11+5,5=24см,10мм
Sinx-cosx - 4cos^3sinx = 4sin^3x ->
sinx - cosx = 4sinx(cos^2x+sin^2x) = 4sinx ->
3sinx = - cosx -> sinx = - cosx/3
sinx^2 + cos^2x = 1 -> cos^2x + cos^2x/9 = 1 ->
10cos^2x = 9 -> cosx = - 3√10/10 cosx = 3√10/10
два равенства:
1. cosx = - 3√10/10 sinx = √10/10 ->
x = 3π/2+arcsin (√10/10) + 2πn
2. cosx = 3√10/10 sinx = - √10/10
x = 2π - arcsin (√10/10) + 2πn