b.an increase in a causes b to decrease
24
step-by-step explanation:
if it takes 8 pounds to make 12 divide 12 by 8 and you get 1.5, 1.5 x 16 = 24
n=9
7 times a number = 7n
decreased by 13 = 7n-13
same as is =
5 times the number = 5n
increased by 5 = 5n+5
7n-13 = 5n+5
2n=18
i think its a and d