The correct answers are B, -7.2, C, -10.5, and D, -15. The inequality x < -7 means that x is less than -7. Keep in mind that the larger a negative number appears to be, the smaller a number it actually is. For example, if you were 1 dollar in debt, then you would have more money than if you were 100 dollars in debt.
x < -7 Given
-7 < -7 Substitute for answer choice A
This inequality is untrue, because -7 is equal to -7.
-7.2 < -7 Substitute for answer choice B
This inequality is true, because -7.2 is less than -7.
-10.5 < -7 Substitute for answer choice C
This inequality is true, because -10.5 is less than -7.
-15 < -7 Substitute for answer choice D
This inequality is true, because -15 is less than -7.
Hope this helps!