1,4,5 Все это нужно сделать !!!

1)
$\frac{1*2*3+2*4*6+4*8*12+7*14*21}{1*3*5+2*6*10+4*12*20+7*21*35} = \frac{2*3* (1+2*4+4*4*4+7*7*7)}{3*5 *(1+2*2*2+4*4*4+7*7*7)} = \frac{2}{5}$

4)
$\frac{16^{n+2}*4^{n-1}}{8^{2n}} = \frac{(2^4)^{n+2}*(2^2)^{n-1}}{(2^3)^{2n}} = \\ \\ = \frac{2^{4(n+2)} *2^{2(n-1)}}{2^{3*2n}} = \frac{2^{4n+8} *2^{2n-2}}{2^{6n}} = \\ \\ = \frac{2^{4n+8+2n-2}}{2^{6n}} = 2^{6n+6-6n}= 2^{6}=64$

5) при х=-3 , у= -5/6
$\frac{ \frac{2}{3} *(-3) * (- \frac{5}{6}) -(-3)^2-(- \frac{5}{6}) -2}{(-3)^2- \frac{-3}{ -\frac{5}{6} } } = \frac{ \frac{2*3*5}{3*1*6} -9 + \frac{5}{6}-2 }{9- \frac{3*6}{1*5} } = \\ \\ = \frac{ \frac{10}{6} + \frac{5}{6} -11}{9-3 \frac{3}{5} } = \frac{2 \frac{1}{2} -11}{5 \frac{2}{5} } =- 8 \frac{1}{2} : 5 \frac{2}{5} = - \frac{17}{2} * \frac{5}{27} = \\ \\ =- \frac{85}{54} = -1 \frac{31}{54}$