Đáp án:
Giải thích các bước giải:
A=1/1×2×2 + 1/2×3×4 + 1/3×4×5 +..... +1/36×37×38 + 1/37×38×39
2A=2/1×2×3 + 2/2×3×4 + 2/3×4×5 +...... + 2/36×37×38 +2/37×38×39
2A=1/1×2 + 1/2×3 - 1/ 2×3 + 1/3×4 - 1/3×4 +.....+1/37×38 - 1/38×39
2A=1/1×2 - 1/38×39
2A=370/741
A=370/741 ÷ 2 = 185/741
=1/1.2.3+1/2.3.4+....+1/37.38.39
=1/1.2-1/2.3+1/2.3-1/3.4+...+1/37.38-1/38.39
=1/1.2-1/38.39
=1/2-1/38.39
=370/7410
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TÁC DỤNG CỦA LỰC ĐÀN HỒI ẢNH HƯỞNG ĐẾN CUỘC SỐNG CHÚNG TA NHƯ NÀO???
Phân tích đa thức thành nhân tử: x^3-x+3x^2y+3xy^2-y^3
giúp mình với. mình đang cần gấp
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Giải thích cụ thể giúp mình nhaaa
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