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