Answer:
20
Step-by-step explanation:
4 + [tex](m-n)^{4}[/tex] ← substitute m = 7 and n = 5 into the expression
= 4 + [tex]7-5)^{4}[/tex]
= 4 + [tex]2^{4}[/tex]
= 4 + 16
= 20
