tính: (7^1997 - 7^1995) : (7^1994.7)
tính:
a, (7\((7^1997-7^1995):(7^1994.7)\)
(7^1997-7^1995):(7^1994.7)
[7^1997 - 7^1995] : [7^1994.7]
=[7^1997 - 7^1995] : 7^1995
=7^1997 : 7^1995 - 7^1995 : 7^1995
=7^2 - 1
=48
nhớ k cho mình nhé
(7^1997-7^1995):(7^1994.7)
(2^8+8^3):(2^5.2^3)
a) 71995.(72-1):71995=72-1=49-1=48
b) [28+(23)3]:25+3=(28+29):28=28(1+2):28=1+2=3
Tính
b, (71997-71995):(71994.7)
(71997-71995):(71994.7) = (71997-71995):71995 = 71997 : 71995 - 71995 : 71995 = 72 : 1 = 49
(71997-71995):(71994.7)
=(71997-71995): 71995
=71997:71995-71995:71995
=72:1
=49:1=49
CHÚC BẠN HỌC GIỎI!!
Tính
\(\left(7^{1997}-7^{1995}\right):\left(7^{1449}.7\right)\)
\(\left(7^{1997}-7^{1995}\right):\left(7^{1994}\cdot7\right)\)
\(=7^{1995}\cdot\left(7^2-1\right):7^{1995}\)
\(=7^2-1\)
\(=49-1\)
\(=48\)
rút gọn:
A=(71997-71995) : (71997 - 7)
( 7^1997 - 7^1995) : (7^1994 x 7)
\(\left(7^{1997}-7^{1995}\right)\div\left(7^{1994}\times7\right)\)
\(=\left(7^{1997}-7^{1995}\right)\div7^{1995}\)
\(=7^{1997}\div7^{1995}-7^{1995}\div7^{1995}\)
\(=7^2-1\)
\(=48\)
P/s tham khảo nha
= 48 =)))))))))))))))))
Tính nhanh
a) 3/5 + 6/11 + 7/13 + 2/5 + 16/11 + 19/13 =
b) 1995/1997 + 1990/1993 + 1997/1994 + 1993/1995 + 997/995
tính nhanh :
a 3/6 + 6/11 + 7/13 + 2/5 + 16/11 + 19/13
b 1995/1997*1990/1993 * 1997/1994 * 1993/1995 * 997/995