Explanation:
4 ⅗ - 2 7/10
let's convert this first into pure fractions :
4×5/5 + 3/5 - (2×10/10 + 7/10) =
= 20/5 + 3/5 - (20/10 + 7/10) =
= 23/5 - 27/10
now, let's bring both fractions to the same denominator (10) :
23/5 × 2/2 - 27/10 = 46/10 - 27/10 = 19/10 = 1 9/10