3v+3(v+2)=30
v+v+2=10
2v=8
v=4 (км/ч)
v+2=4+2=6 (км/ч)
<u><em>Ответ: 4км/ч и 6км/ч</em></u>
Х2-18х+80 / 5х-50 = х2-10х - 8x+80 / 5х-50 =
= x(х-10) - 8(x-10) / 5(х-10) =
= (х-10) (x - 8) / 5(х-10) =
= (x - 8) / 5
при х= -12 ; (-12 - 8) / 5 = - 4
при х= 48 ; ( 48 - 8) / 5 = 8
A) sinx = √3/2; x =
![(-1)^{n} π/3 +πn, [tex] б) /cosx = tgx - √3 =0; tgx = √3; x =arctg√3 +πn, x = π/3 +πn, n∈Z. г)cosx[tex] \neq 0; x \neq \pi /2+ \pi n,n](https://tex.z-dn.net/?f=+%28-1%29%5E%7Bn%7D%C2%A0%CF%80%2F3+%2B%CF%80n%2C+%5Btex%5D%C2%A0+%D0%B1%29+%C2%A0%2Fcosx+%3D+tgx+-%C2%A0%E2%88%9A3+%3D0%3B+%C2%A0tgx+%3D%C2%A0%E2%88%9A3%3B+x+%3Darctg%E2%88%9A3+%2B%CF%80n%2C+%C2%A0x+%3D%C2%A0%CF%80%2F3+%2B%CF%80n%2C+n%E2%88%88Z.+%D0%B3%29cosx%5Btex%5D+%5Cneq+0%3B+++x+%5Cneq++%5Cpi+%2F2%2B+%5Cpi+n%2Cn)
∈Z; sinx (sin2x + 1) = 0;
sinx = 0; x = πn, sin2x =- 1; sinx = -1/2; x =
2) 2 cosx/2 меньше 1; cosx/2 = 1/2; x/2 =π/6 +2πn, n∈Z; x =+- π/3 +πn,n∈z;
(p-g)/3g=( -1,6-6,4)/(3·6,4)=(-8)÷(3·6,4)= -1: (3·0,8) = -1:2,4=-1:24/10= - 10/24= -5/12.