Answer
123
Work Step by Step
Substitute the given values and simplify.
$(3c^2-3d)^2-21$
$=(3(3^2)-3(5))^2-21$ simplify the exponent in parentheses
$=(3(9)-3(5))^2-21$ multiply in parentheses
$=(27-15)^2-21$ subtract in parentheses
$=12^2-21$ solve exponent
$=144-21$ subtract
$=123$
