28 oranges!!!!
basically to start off we know 8 oranges = $1.50 so we have to find the rate. By dividing $1.50 by two you then figure out 4 oranges
= $0.75. So now by adding 1.50 up 2 times you get $4.50 which would equal 24 oranges BUT you have to find how much oranges if you can buy with $5.25 so you add 0.75, which you figured out means 4 oranges in the beginning sooooooo you add 4 oranges and 0.75 cents to the amount from before ($4.50 and 24 oranges) which gives you 28 oranges.
28 oranges = $5.25
(i am srry tho, i don't know what parameters means. i've never learned it before but i hope this maybe helps)