(50+5/8)*1/5簡便計算

(50+5/8)*1/5簡便計算


(50+5/8)*1/5
=50x1/5+5/8x1/5
=10+1/8
=10又1/8
如果本題有什麼不明白可以追問,



50÷2.5+1.8×4.5簡便運算
50÷2.5+1.8×4.5怎樣簡便運算?


50÷2.5+1.8×4.5
=(50×4)÷(2.5×4)+0.9×2×4.5
=200÷10+0.9×9
=20+8.1
=28.1



1+2+3+4+5+6+7+8+……49=?


1+49+2+48+3+47+…+24+26+25
=50×24+25
=1225



計算1+(2+3)-(4+5)+(6+7)-(8+9)······-(48+49)+50=


1+(2+3)-(4+5)+(6+7)-(8+9)······-(48+49)+50
=1+48÷4×(-4)+50
=1-48+50
=3