1км-1000м
112км-112000м
выходит 112000м/ч, теперь..
1ч-60мину
1мин-60сек.
60*60=3600сек
112000:3600=31(1)с округлением≈31,
выходит,
31м/сек
Через второй замечательный предел:
![\lim_{x\to\infty}({x+2\over2x-1})^{1\over x}=\lim_{x\to\infty}e^{ln({x+2\over2x-1})^{1\over x}}=\lim_{x\to\infty}e^{{1\over x}ln({1\over2}(1+{5\over2x-1}))}=\\=\lim_{x\to\infty}e^{{1\over x}ln({1\over2}e^{5\over2x-1})}=\lim_{x\to\infty}e^{{1\over x}(ln({1\over2})+{5\over2x-1})}=\\=\lim_{x\to\infty}e^{{ln({1\over2})\over x}+{5\over2x^2-x}}=e^0=1](https://tex.z-dn.net/?f=%5Clim_%7Bx%5Cto%5Cinfty%7D%28%7Bx%2B2%5Cover2x-1%7D%29%5E%7B1%5Cover+x%7D%3D%5Clim_%7Bx%5Cto%5Cinfty%7De%5E%7Bln%28%7Bx%2B2%5Cover2x-1%7D%29%5E%7B1%5Cover+x%7D%7D%3D%5Clim_%7Bx%5Cto%5Cinfty%7De%5E%7B%7B1%5Cover+x%7Dln%28%7B1%5Cover2%7D%281%2B%7B5%5Cover2x-1%7D%29%29%7D%3D%5C%5C%3D%5Clim_%7Bx%5Cto%5Cinfty%7De%5E%7B%7B1%5Cover+x%7Dln%28%7B1%5Cover2%7De%5E%7B5%5Cover2x-1%7D%29%7D%3D%5Clim_%7Bx%5Cto%5Cinfty%7De%5E%7B%7B1%5Cover+x%7D%28ln%28%7B1%5Cover2%7D%29%2B%7B5%5Cover2x-1%7D%29%7D%3D%5C%5C%3D%5Clim_%7Bx%5Cto%5Cinfty%7De%5E%7B%7Bln%28%7B1%5Cover2%7D%29%5Cover+x%7D%2B%7B5%5Cover2x%5E2-x%7D%7D%3De%5E0%3D1)
По-человечески:
![\lim_{x\to\infty}({x+2\over2x-1})^{1\over x}=\lim_{x\to\infty}({1\over2}+{5\over2(2x-1)})^{1\over x}=({1\over2}+0)^0=1](https://tex.z-dn.net/?f=%5Clim_%7Bx%5Cto%5Cinfty%7D%28%7Bx%2B2%5Cover2x-1%7D%29%5E%7B1%5Cover+x%7D%3D%5Clim_%7Bx%5Cto%5Cinfty%7D%28%7B1%5Cover2%7D%2B%7B5%5Cover2%282x-1%29%7D%29%5E%7B1%5Cover+x%7D%3D%28%7B1%5Cover2%7D%2B0%29%5E0%3D1)
28:2=14(лет)было дочери
50-14=36(лет ) назад было дочери
Ответ :36лет
EM- x
DM- 5x
x+5x=30
6x=30
x=5
EM=5 см
DM=25 cм
1)(2а^2)×1/4а^2=1/2а^4
2)(-3в^4)^5×1/27в^3=-243В^20×1/27В^3= -9в^23
3)(-5а^3в^2)^2×(-0,2а^2в^3)^-1=25а^6в^4×2а^-2в^-3=50а^4в