(3•96-84•3)+(5•84-72•5)+(7•72-60•7)+(9•60-48•9)+(11•48-36•11)+(13•36-24•13)=3(96-84)+5(84-72)+7(72-60)+9(60-48)+11(48-36)+13(36-24)=3×12+5×12+9×12+11×12+13×12=12(3+5+7+9+11+13)=12×47=576
Ответ: С
Без проблем :3
3cos 2a - sin^2a - cos^2a = 3cos2a-(cos^2a-sin^2a)=3cos2a-cos2a=2cos 2a
cos2a=cos^a-sin^2a
4м6дм,6дм,4м10см,87дм,1м40см,90см,3м,43дм
1) 5.6× 8× 35=1568<br />16×0.7×20= 224<br />1568÷ 224=7
2) 14.4×0.5×4.2=30.23
0.7×15×1.2=12.6
30.24÷12.6=2.4
У / 8,4 = 1 1/8 / 6 3/4
у/ 8,4 = 1,125 / 6 ,75
у *6,75 = 8,4 * 1,125
у = 8,4 * 1,125 / 6,75
у = 9,45/6,75
у = 1,4