You first have to find out the total number of questions there was on the unit test. To do that you write 90 over 100 equals 45 over x. X represents the total number of questions. Then cross multiply. you should get 90x=4500.then divide 4500 by 90 and the answer should be x=50. then take 50 subtract 2 and you should get 48. then take 48 and divide it by 50. the answer you should get is .96. then take .96 multiply it by 100 and you should get 96. so Emmanuel's percent on the unit test is 96%.