Answer:
The value of the expression is 61.
Step-by-step explanation:
Consider the provided expression.
[tex]x^4-y[/tex]
In order to evaluate the expression [tex]x^4-y[/tex] at x = 3 and y = 20, substitute the value of x = 3 and y = 20 in the above expression.
[tex](3)^4-20[/tex]
[tex]81-20[/tex]
[tex]61[/tex]
Hence, the value of the expression is 61.