Order the angel's from least to greatest with numbers 21, 24, 17

Given this information, which expression must represent the value of b?

Select the correct answer from the drop-down menu. subtracting 3xy^2 from 8xy^2 gives the same result as the expression. [tex]3xy ^{2} - 8xy ^{2} [/tex][tex] { - 7xy}^{2} - {2xy}^{2} [/tex][tex] {7xy}^{2} - {2xy}^{2} [/tex]

Twelve less than a number is at most 20