1km = 1.000 m
1m = 100 cm
1 dm = 10 cm
cm = 10 mm
1kg = 1.000 g
1t = 1000kg
1.100:77=~14
64.800:72 = 0.9
810:18=45
114 : 76=1.5
3.440 : 43=80
4.592 : 14=328
tg^2(a) = sin^2(a) / cos^2(a)
6 = 6sin^2(a) + 6cos^2(a) - основное тригонометрическое тождество
5sin^2(a) + 13cos^2(a) - 6sin^2(a) - 6cos^2(a) = 0
7cos^2(a) = sin^2(a)
tg^2(a) = 7
15 см = 1 дм 5 см
1 дм 7см = 17 см