Consider u = {x|x is a positive integer greater than 1}. which is an empty set? {x|x ∈ u andone-half is prime} {x|x ∈ u and 2x is prime} {x|x ∈ u andone-half can be written as a fraction} {x|x ∈ u and 2x can be written as a fraction}

Sundar used linear combination to solve the system of equations shown. he did so by multiplying the first equation by 5 and the second equation by another number to eliminate the y-terms. what number did sundar multiply the second equation by? 2x+9y=41 3x+5y=36