8 x (5 x 2 + 3)=104 because 5 x 2 is 10, 10 + 3 is 13, and 13 x 8 is 104.
It would be 1)2.2 because 183.59/85 is 2.15988235. If you multiply: 2.15988235*85, you get 183.59. So your math is all correct, so unless your formula is wrong, your answer is correct. So I guess you're supposed to round up.
= 6x + 6x - 6x × 7 + 6xy - 7y
36x2 - 42x + 6xy - 7y
645 rounded to the nearest 10 is 650, as 5 in the ones place rounds up.