Tính :
A = \(\dfrac{2.3.5+4.9.35+6.9.35+10.21.40}{2.3.7+4.9.35+6.9.49+10.21.56}\)
Những câu hỏi liên quan
A=2.3.5+4.9.25+6.9.35+10.21.40/2.3.7+4.9.35+6.9.49+10.21.56
A=5.(2.3+4.9.5+6.9.7+10.21.8)/7.(2.3+4.9.5+6.9.7+10.21.8)
A=5/7
Đúng 0
Bình luận (0)
2.3.5+4.9.25+6.9.35+10.21.40/2.3.7+4.9.35+6.9.49+10.21.56
6 tháng 3 2016 lúc 16:06
Tính : \(A=\frac{2.3.5+4.9.25+6.9.35+10.21.40}{2.3.7+4.9.35+6.9.49+10.21.56}\)
Ta có : \(A=\frac{2.3.5.1.1.1+2.3.5.2.3.5+2.3.5.3.3.7+2.3.5.5.7.8}{2.3.7.1.1.1+2.3.7.2.3.5+2.3.7.3.3.7+2.3.7.5.7.8}\)
\(=\frac{2.3.5\left(1.1.1+2.3.5+3.3.7+5.7.8\right)}{2.3.7\left(1.1.1+2.3.5+3.3.7+5.7.8\right)}=\frac{2.3.5}{2.3.7}=\frac{5}{7}\)
Đúng 0
Bình luận (0)
Xem thêm câu trả lời
RÚT GỌN BIỂU THỨC
\(\frac{2.3.5+4.9.25+6.9.35+10.21.40}{2.3.7+4.9.35+6.9.49+10.21.56}\)
Rút gọn
e/2.3.5+4.9.25+6.9.95+10.21.40/2.3.7+4.9.35+6.9.49+10.21.56+4.9.35
RÚT GỌN BIỂU THỨC
\(\frac{2.3.5+4.9.25+6.9.35+10.21.40}{2.3.7+4.9.35+6.9.49+10.21.56}\)
Tính:
A
2
.
3
.
5
+
4
.
9
.
25
+
6
.
9
.
35
+
10
.
21
.
40
2
.
3
....
Đọc tiếp
Tính:
A = 2 . 3 . 5 + 4 . 9 . 25 + 6 . 9 . 35 + 10 . 21 . 40 2 . 3 . 7 + 4 . 9 . 35 + 6 . 9 . 49 + 10 . 21 . 56
Tính:
A
2
.
3
.
5
+
4
.
9
.
25
+
6
.
9
.
35
+
10
.
21
.
40
2
.
3
....
Đọc tiếp
Tính:
A = 2 . 3 . 5 + 4 . 9 . 25 + 6 . 9 . 35 + 10 . 21 . 40 2 . 3 . 7 + 4 . 9 . 35 + 6 . 9 . 49 + 10 . 21 . 56
Giúp nha , người nhà cả mà . Thick cho
a) A= 2.3.5+4.9.25+10.21.40 / 2.3.7+4.9.35+6.9.49+10.21.56
b) (1/4 - 1 ).(1/9-1).(1/16-1).....(1/400-1)
\(B=\left(\frac{1}{4}-1\right)\left(\frac{1}{9}-1\right)\left(\frac{1}{16}-1\right)...\left(\frac{1}{400}-1\right)\)
\(-B=\left(1-\frac{1}{4}\right)\left(1-\frac{1}{9}\right)\left(1-\frac{1}{16}\right)...\left(1-\frac{1}{400}\right)\)
\(-B=\frac{3}{4}\cdot\frac{5}{9}\cdot\frac{15}{16}\cdot...\cdot\frac{399}{400}\)
\(-B=\frac{\left(1\cdot3\right)\left(2\cdot4\right)\left(3\cdot5\right)...\left(19\cdot21\right)}{\left(2\cdot2\right)\left(3\cdot3\right)\left(4\cdot4\right)...\left(20\cdot20\right)}\)
\(-B=\frac{\left(1\cdot2\cdot3\cdot...\cdot19\right)\left(3\cdot4\cdot5\cdot...\cdot21\right)}{\left(2\cdot3\cdot4\cdot...\cdot20\right)\left(2\cdot3\cdot4\cdot...\cdot20\right)}\)
\(-B=\frac{1\cdot21}{20\cdot2}\)
\(-B=\frac{21}{40}\)
\(B=\frac{-21}{40}\)
Đúng 0
Bình luận (0)
\(A=\frac{\text{2.3.5+2.2.3.3.5.5+2.5.3.7.2.2.2.5 }}{2.3.7+2.2.3.3.7.5+2.3.3.3.7.7+2.5.3.7.7.2.2.2}\)
\(=\frac{2.3.5.\left(1+2.3.5+2^3.5.7\right)}{2.3.7.\left(1+2.3.5+3.3.7+2^3.5.7\right)}\)
\(=\frac{2.3.5}{2.3.7.3.3.7}=\frac{5}{441}\)
Đúng 0
Bình luận (0)