(+ 9 1 / 2) + (- 3 3 / 7) + 8 1 / 2 + (+ 3 / 7) simple calculation

(+ 9 1 / 2) + (- 3 3 / 7) + 8 1 / 2 + (+ 3 / 7) simple calculation

(+ 9 1 / 2) + (- 3 3 / 7) + 8 1 / 2 + (+ 3 / 7)
=9 1 / 2 + (- 3 3 / 7) + 8 1 / 2 + 3 / 7
=(9 1 / 2 + 8 1 / 2) + (- 3 3 / 7 + 3 / 7)
=18 - (3 and 3 / 7-3 / 7)
=18-3
=15