6. Ответ: 3) 1, 3, 5, 7, ...
7. b/c-(b²+c²)/(bc)-c/b=(b²-b²-c²-c²)/(bc)=-2c²/(bc)=-2c/b=-2*0,9/(-4)=0,45.
![3a=3*(4;-4;2)=(3*4;3*(-4);3*2)=(12;-12;6);](https://tex.z-dn.net/?f=3a%3D3%2A%284%3B-4%3B2%29%3D%283%2A4%3B3%2A%28-4%29%3B3%2A2%29%3D%2812%3B-12%3B6%29%3B)
|3a|= ![\sqrt{12^2+(-12)^2+6^2}=18](https://tex.z-dn.net/?f=%5Csqrt%7B12%5E2%2B%28-12%29%5E2%2B6%5E2%7D%3D18)
ответ модуль вектора 3а 18
1) -2, 5×8+,2, 5×3х =20+ 7,5х
2) 0,2×18х+0, 2×14= 3,6х+2, 8
3) 20+7, 5х+3, 6х+2, 8 =22, 8+11, 1х
ответ: 22,8+11, 1х
. . . . . . . . . . . . . . . .
А2(а-2)-а(а-3)2
а•(а•(-а-2)-(а-3)2
а•(а2-2а-(а2-6а+9))
а•(а2-2а-а2+6а-9)
а•(4а-9)