Find the extreme values of f subject to both constraints. (If an answer does not exist, enter DNE.) f(x, y, z) = yz + xy; xy = 1, y^2 + z^2 = 25

i think its a and d

step-by-step explanation:

answer: first option i.e. 'a' is correct.

step-by-step explanation:

since we have given that

number of minutes to wrap a small gift box = 4 minutes

we need to find the number of gifts to be wrapped in 5 minutes

since there is a direct variation, as the number of minutes will increase with   number of gifts to be wrapped.

so, let the number of gifts to be wrapped in 5 minutes be x.

so, it becomes,

hence, first option 'a'   is correct.