Answer: x = 3.030631 approximately
Explanation:
If you want to solve for x, then you could follow these steps:
[tex]18 = 1.57*x^{2.2}\\\\18/1.57 = x^{2.2}\\\\11.464968 \approx x^{2.2}\\\\x^{2.2} \approx 11.464968\\\\x \approx (11.464968)^{\frac{1}{2.2}}\\\\x \approx 3.030631\\\\[/tex]
In the second to last step, we have the value 11.464968 raised to the exponent of 1/(2.2) which is done to undo the exponent of 2.2 in the previous line. The rule used is [tex]a^b = c \to a = c^{1/b}[/tex]
