Плиз помогите (-0,5)^-4 -625^0,25 - ( 2 1\4)^-1 + 19(-3)^-3

Решите задачу:

$(-0,5)^{-4} -625^{0,25} - ( 2 1:4)^{-1} + 19(-3)^{-3}= \\ \\ (-\frac{1}{2})^{-4}-(5^4) ^{ \frac{1}{4} }- \frac{4}{21}+ \frac{19}{(-3)^3}=(-2)^4-5- \frac{4}{21}- \frac{19}{27}= \\ \\ 16-5-\frac{4}{21}- \frac{19}{27}=10 \frac{17}{21}- \frac{19}{27}= \\ \\ 10 \frac{17*9-19*7}{189}=10 \frac{153-133}{189}=10 \frac{20}{189}$