First turn the whole numbers into mixed fractions: 1 1/2 multiply the whole number by the denominator then add it to the numerator which will make 3/2 doing the same thing on 1 2/3, you get 5/3 finding the LCM of 5/3, 3/2 and 3/4, you get 12 multiplying 4/4 to 5/3, you get 20/12 multiplying 6/6 to 3/2, you get 18/12 multiplying 3/3 to 3/4, you get 9/12 now you can add them easily and you get 47/20 turning that into a whole fraction, you get 2 7/20