Question

Скоротіть дріб: 4*** +4**2 5 1) 76 натуральне число;​

Answer 1

$\displaystyle\bf\\1)\\\\\frac{4^{n+3}+4^{n+2} }{5} =\frac{4^{n+2} \cdot(4+1)}{5} =\frac{4^{n+2} \cdot 5}{5} =4^{n+2} \\\\2)\\\\\frac{x+x^{7} }{x^{-4}+x^{2} } =\frac{x\cdot(1++x^{6}) }{\dfrac{1}{x^{4} }+x^{2} } =\\\\\\=\frac{x\cdot(1++x^{6}) }{\dfrac{1+x^{6} }{x^{4} } } =\frac{x\cdot(1++x^{6})\cdot x^{4} }{1+x^{6} } =x^{5}$