Answer:
360 and 16.8
Step-by-step explanation:
Substitute x = 12 into the expressions
a = [tex]\frac{5(12)^2}{2}[/tex] = [tex]\frac{5(144)}{2}[/tex] = [tex]\frac{720}{2}[/tex] = 360
b = [tex]\frac{2(12)^2(12-5)}{10(12)}[/tex] = [tex]\frac{2(144)(7)}{120}[/tex] = [tex]\frac{2016}{120}[/tex] = 16.8
