2 5/8= 21/8
3 1/4=13/4
2 2/3=8/3
21/8*8/3+13/4=7+13/4= 28/4+13/4=41/4= 10 1/4
(4 - 14/33 * 1 целая 1/21) * 5 целых 5/8 = 20
1) 14/33 * 1 целая 1/21 = 14/33 * 22/21 = (2*2)/(3*3) = 4/9
2) 4 - 4/9 = 3 целых 9/9 - 4/9 = 3 целых 5/9
3) 3 целых 5/9 * 5 целых 5/8 = 32/9 * 45/8 = (4*5)/(1*1) = 20
1.) 5/21 + 2/7 = 5/21 + 6/21 = 11/21
2.) 5/12 + 3/8 = 10/24 + 9/24 =
= 19/24
3.) 5/12 + 1/12 + 1/5 = 6/12 + 1/5 =
= 30/60 + 12/60 = 42/60 = 7/10
Ответ:
Пошаговое объяснение:
cosα=(1*4+2*3+(-1)*0)/((√(1²+2²+(-1)²)*√(4²+3²+0²))=(4*+6-0)/(√6*√25)=
=10/(5*√6)=2/√6=2*√6/6=√6/3≈0,8165.