№1.sin(180+20)cos(270+40)tg(180+10) -sin20 sin40 tg10 sin 20
------------------------------------------------------------ = ------------------------------ = ------------- =
sin(180-10)sin(180+40)ctg(270-10) -sin10sin 40 tg 10 sin 10
2 cos10 sin10
= -------------------------- =2 cos 10
sin 10
ответ "С"