<span>"Each box has 10 bags in it. each bag has 10 blocks in it."
That means that in each box, there are 100 blocks. Tiara just needs to buy [3 boxes] and she'll get [84 blocks left over].</span>
4 liters is slightly bigger
15, median is the number in the middle, (i.e. median of 3, 4, 8, 9, 10, is 8.)

Answer : This is because when 5z minus 5z, it is nullified, with no way to determine the value of z. 5z - 5z = 0
That is why there is no solution for this equation.
Hope this helps. - M