Toán Tính A = 1/2 +5/6 +11/12 + 19/20 + 29/30 + 41/42 + 55/56 + 71/72 + 89/90 15/09/2021 By Lyla Tính A = 1/2 +5/6 +11/12 + 19/20 + 29/30 + 41/42 + 55/56 + 71/72 + 89/90
Đáp án: Giải thích các bước giải: A = (1 -1/2) + (1 – 1/6) + (1 – 1/12) + (1 – 1/20 ) + …+ (1 – 1/ 90) = (1+1+1+1+1+1+1+1+1) – ( 1/2 – 1/6 – 1/12 – 1/ 20 – …- 1/90) = 9 -(1/1×2+1/2×3+1/3×4+1/4×5+…+1/9×10)= 9-1/2+1/2+1/3+1/3+1/4+…+1/9-1/10 = 9 – (1-1/10) = 81/10 Xin hay nhất về nhóm với ạ! Chúc bạn học tốt!^^ #hancuteo Trả lời
Giải thích các bước giải: 1/2+5/6+11/12+19/20+29/30+41/42+55/56+71/72+89/90 =1−1/2+1−1/6+1−1/12+1−1/20+1−1/30+1−1/42+1−1/56+1−1/72+1−1/90 =9–(1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90) =9–[1/1.2+1/2.3+1/3.4+1/4.5+1/5.6+1/6.7+1/7.8+1/8.9+1/9.10] =9–(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+1/8−1/9+1/9−1/10) =9–(1–1/10)=9–9/10=81/10 Trả lời
Đáp án:
Giải thích các bước giải:
A = (1 -1/2) + (1 – 1/6) + (1 – 1/12) + (1 – 1/20 ) + …+ (1 – 1/ 90)
= (1+1+1+1+1+1+1+1+1) – ( 1/2 – 1/6 – 1/12 – 1/ 20 – …- 1/90)
= 9 -(1/1×2+1/2×3+1/3×4+1/4×5+…+1/9×10)=
9-1/2+1/2+1/3+1/3+1/4+…+1/9-1/10
= 9 – (1-1/10)
= 81/10
Xin hay nhất về nhóm với ạ!
Chúc bạn học tốt!^^
#hancuteo
Giải thích các bước giải:
1/2+5/6+11/12+19/20+29/30+41/42+55/56+71/72+89/90
=1−1/2+1−1/6+1−1/12+1−1/20+1−1/30+1−1/42+1−1/56+1−1/72+1−1/90
=9–(1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90)
=9–[1/1.2+1/2.3+1/3.4+1/4.5+1/5.6+1/6.7+1/7.8+1/8.9+1/9.10]
=9–(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+1/8−1/9+1/9−1/10)
=9–(1–1/10)=9–9/10=81/10