Question

вычислите удобным способом 20-18,5+21-17,5+20-16,5+19-15,5+18-14,5

Answer 1

20+21+20+19+18-18.5-17.5-16.5-15.5-14.5=98-82.5=15.5

Answer 2

20-18,5+21-17,5+20-16,5+19-15,5+18-14,5 =  (20+20) + (21+19) + (- 15,5 - 14,5) + +  (-16,5 - 15,5) + (-18,5 - 17,5) + 18 = 40 + 40 - 30 - 32 - 36 + 18 = 80 - 62 - 18 =  80 - - 80 = 0