Which of the following is a monomial?
a. x^-2
b. x
c.(x+1)^2
d. y/x

Anyone know? will mark brainliest if correct

Solve the equation x/4 - 5= -8 -27 -12 -7 12

Pyotr tchaikovsky sporting goods operates on a 45% overhead based on the selling price, which results in an overhead of $65.34 on the newest version of an air hockey game set. if the air hockey game set costs pyotr tchaikovsky sports $49.32, find the selling price, the markup, and the net profit.