計算(m^2-9)/[m(m-3)+m-3]

計算(m^2-9)/[m(m-3)+m-3]


(m^2-9)/[m(m-3)+m-3]
=(m+3)(m-3)/[(m+1)(m-3)]
=(m+3)/(m+1)



1/3+1/6+1/10+1/15+1/21+1/28+1/36+1/45用最簡單的方法做出答案.


1/3(1+1/2)+1/5(1/2+1/3)+1/7(1/3+1/4)+1/9(1/4+1/5)+1/11(1/5+1/6)+1/13(1/6+1/7)+1/15(1/7+1/8)=1/3*3/2+1/5*5/6+1/7*7/12+1/9*9/20+1/11*11*30+1/13*13/42+1/15*15/56 =1/2+1/6+1/12+1/20+1/30+1/42+1/56 =1-1/2+1/2-1/3+1/3-1/4+1/4-1/5 +1/5-1/6+1/6-1/7+1/7-1/8 =1-1/8 =7/8
滿意請採納



用簡便法125÷(50÷6)怎麼算


125÷5×6÷10