Question

Срочно,помогите пожалуйста!

Answer 1

1)$a_{n+1}=a_n+3\\a_{1+1}=a_1+3\\a_2=5+3=8\\a_3=8+3=11\\a_4=5+3*4=14\\a_5=14+3=17\\a_{10}=a_1+3*9=5+27=32\\a_{10}=32$
2)$\frac{1}{x}- \frac{x+5y}{5xy}= \frac{5y-x+5y}{5xy}= \frac{10y-x}{5xy}= \frac{10 *\frac{1}{8}- \sqrt{28} }{5* \sqrt{28}* \frac{1}{8} }= \frac{10}{8}* \frac{8}{10}-1=0$