Answer: A
Explanation:
Focus on what it is saying. It is saying that 5x IS LESS THAN OR EQUAL TO 15.
So we are looking for smaller numbers, that is, values of x, in order to make this statement true.
So on a number line we are looking for the left part shaded in.
Furthermore... notice that the sign has "or equal to". Thus the circle is going to be shaded in. The circle is not going to be open and empty. Through this we have eliminated answers B and C.
So the answer is A because— remember— the left side of the number line is shaded. It encompasses negative numbers. A negative number times 5 will definitely be less than 15.