Which expression is equivalent to pq? 1. p+9 2.p-q 3.p/q 4.qp

Hello. 

So the expression pq means: p·q or p(q) so we need to find something equivalent to p times q.

We can easily see that Choice 4: qp is the correct answer. Because qp means: q·p or q(p). 

Thus, 4.qp is your answer. 
You're welcome.