Explanation:
you know what 3/20 is in decimal form ?
it is literally dividing 3 by 20. and the result is 0.15.
you can get this skating by converting the fraction to n/100.
it means to multiply numerator and denominator by 5
3/20 × 5/5 = 15/100 = 0.15
so, the first number is actually
-1,098.15
now the difference is not so difficult anymore, right ?
-1,098.15 - -2,784.72 = -1,098.15 + 2,784.72 = 1,686.57