That's not an inequality.
B. 7
49 divided by 7 is 7.
Rachel bought a collection of buttons.
2/4 of the buttons are yellow. 2/4 * 8 = 1/2 * 8 = 4 yellow buttons
2/8 of the buttons are red. 2/8 * 8 = 1/4 * 8 = 2 red buttons
Therefore, because we know that 4 of the buttons are yellow and 2 of the buttons are red, and we know that 4 > 2, we know that more yellow buttons were bought.
The recursive formula that models the amount owed is
an = a(n-1) -75; a1 = 600.
This formula is for AFTER the first month of payment, this is why the first term is 700-100 = 600. This also means that n > 1.