Answer
C: 2y +3$\leq$x
Work Step by Step
The question uses the word at least when describing the cost of the hardcover book (x) so we know that there is $\leq$ symbol opening towards the cost (x). Now the question uses the phrase three more than twice the cost (y). The "three more than" can be represented by adding 3 to y and the phrase "twice the cost" can be represented by multiplying the cost (y) by a scalar of 2. So we get the inequality:
2y+3$\leq$x
