518x5=2,590, So your estimate is about 2,600, Because we want to round up, So we look in the tens place and we see a nine, so that means we go up on, Also 5 and up means we gonna round up and 5 and below means we gonna round down.
Yes, the price is proportional because you can reduce their fractions:
16/4 = 4
24/6 = 4
36/9 = 4
56/14 = 4
Put in 1 for x and which problem gives you 7
the answer is y=7x
6 i believe but im not sure