Question

what should be your first step in solving -3x>0

Answer 1

is it x or multiply sign

Answer 2

You have to isolate the x. Since x is being multiplied you have to divide both sides by what it's being multiplied by to cancel out the x.
\[\frac{ -3x }{ -3 } >\frac{ 0 }{ -3}\]
In an inequality, you have to flip the sign when dividing or multiplying both sides by a negative number. Since zero divided by -3 is zero, here's your answer:
\[x < 0\]