(78 n + 42)^2, when n = 91

So evaluate/subsitue
the equation becomes
(78 times 91+42)^2

pemdas
do what's inside the parenthasees first

start over
parenthasees
exponents
multiplication and division yes 78 times 91
addition  and subtraction so

78 times 91 is first
78 times 91=7098
addition
(7098+42)^2
(7140)^2

restart

parentasees simplified
exponents
7140^2=50,979,600

D. FH

Diameter-
a straight line passing from side to side through the center of a body or figure, especially a circle or sphere.