Step-by-step explanation:
[tex]y = \frac{4}{x} + \sqrt{x + 0.2} - 5x[/tex]
[tex]x = \frac{4}{5} [/tex]
[tex]y = \frac{4}{1} \div \frac{4}{5} + \sqrt{ \frac{4}{5} + 0.2} - 5 \times \frac{4}{5} [/tex]
[tex] \frac{4}{1} \times \frac{5}{4} + \sqrt{0.8 + 0.2} - 4[/tex]
[tex]5 + \sqrt{1} - 4[/tex]
[tex]5 + 1 - 4 \\ 6 - 4 = 2[/tex]
