Answer
a) $x+15$
b)$15 \gt x$
Work Step by Step
a) To translate the given sentence into an expression, we will use x for the unknown number. "15 more than a number" requires us to add 15 to the number, x. We start with x and add 15 to it. Therefore, the answer is: $x+15$
b) To translate the given sentence into an expression, we will use x for the unknown number. "15 is more than a number" is an inequality expressing that 15 is greater than a number, x. Therefore, we will use the "greater than" sign, and our answer is: $15 \gt x$
