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giúp mik vs ạk. mik c.ơn ạ
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Những câu hỏi liên quan
P
1 tháng 7 2023
Bài 5:
a) \(0,24\cdot-\dfrac{15}{4}=\dfrac{6}{25}\cdot-\dfrac{15}{4}=\dfrac{6\cdot-15}{25\cdot4}=-\dfrac{90}{100}=-\dfrac{9}{10}\)
b) \(4,5\cdot\dfrac{-4}{9}=\dfrac{9}{2}\cdot\dfrac{-4}{9}=\dfrac{9\cdot-4}{2\cdot9}=-\dfrac{4}{2}=-2\)
c) \(3,5\cdot-1\dfrac{2}{5}=\dfrac{7}{2}\cdot\dfrac{-7}{5}=\dfrac{7\cdot-7}{2\cdot5}=-\dfrac{49}{10}\)
P
1 tháng 7 2023
Bài 6:
a) \(1\dfrac{1}{17}\cdot\left(-2\dfrac{1}{8}\right)=\dfrac{18}{17}\cdot\dfrac{-17}{8}=\dfrac{18\cdot-17}{17\cdot8}=\dfrac{-18}{8}=-\dfrac{9}{4}\)
b) \(\left(-2\dfrac{1}{3}\right)\cdot1\dfrac{1}{14}=-\dfrac{7}{3}\cdot\dfrac{15}{14}=\dfrac{-7\cdot15}{3\cdot14}=-\dfrac{5}{2}\)
c) \(1,25\cdot\left(-3\dfrac{3}{8}\right)=\dfrac{5}{4}\cdot-\dfrac{27}{8}=\dfrac{5\cdot-27}{4\cdot8}=-\dfrac{135}{32}\)
PT
0
R
1
RY
24 tháng 4 2022
a. f(\(\dfrac{-1}{2}\)) = \(4.\left(\dfrac{-1}{2}\right)^2+3.\left(\dfrac{-1}{2}\right)-2\)
= \(4.\dfrac{1}{4}-\left(\dfrac{-3}{2}\right)-\dfrac{4}{2}\)
= \(\dfrac{2}{2}+\dfrac{3}{2}-\dfrac{4}{2}\)
= \(\dfrac{1}{2}\)
VN
Võ Ngọc Phương
VIP
11 tháng 9 2023
\(400906=4\times100000+9\times100+6\)
\(abcde=a\times10000+b\times1000+c\times100+d\times10+e\)
\(#Wendy.Dang\)
SV
Sinh Viên NEU
CTVVIP
4 giờ trước (14:26)
He said that he had been very thirsty.
She told me to be careful.
He wondered why I hadn't told him.
He said that he could not take them home.
He told us not to go to the beach alone.
SV
Sinh Viên NEU
CTVVIP
4 giờ trước (14:27)
He wanted to know if we had been shopping for food.
He asked what the time was.
She asked me when we would see each other again.
He wanted to know where they had lived before moving there.
He asked her if she would be at Tom's party.
P
10 tháng 11 2023
\(A=7+7^2+7^3+7^4+7^5+7^6+7^7+7^8\)
\(A=\left(7+7^3\right)+\left(7^2+7^4\right)+\left(7^5+7^7\right)+\left(7^6+7^8\right)\)
\(A=7\cdot\left(7+7^2\right)+7^2\cdot\left(1+7^2\right)+7^5\cdot\left(1+7^2\right)+7^6\cdot\left(1+7^2\right)\)
\(A=7\cdot50+7^2\cdot50+7^5\cdot50+7^6\cdot50\)
\(A=50\cdot\left(7+7^2+7^5+7^6\right)\)
\(A=5\cdot10\cdot\left(7+7^2+7^5+7^6\right)\)
Ta có: 5 ⋮ 5
⇒ \(A=5\cdot10\cdot\left(7+7^2+7^5+7^6\right)\) ⋮ 5 (đpcm)
NT
Nguyễn Thị Thương Hoài
Giáo viên
VIP
10 tháng 11 2023
A = 7 + 72 + 73 + 74 + 75 + 76 + 77 + 78
A = (7 + 73) + (72+ 74) + (75 + 77) + (76 + 78)
A = 7.(1 + 72) + 72.(1 + 72) + 75.(1 + 72) + 76.(1 + 72)
A = 7.( 1 + 49) + 72.( 1 + 49) + 75.(1 + 49) + 76. (1 + 49)
A = 7.50 + 72.50 + 75.50 + 76.50
A = 50.(7 + 72 + 75 + 76)
Vì 50 ⋮ 5 nên A = 50.(7 + 72 + 76) ⋮ 5 đpcm
NL
Nguyễn Lê Phước Thịnh
CTVHS
7 tháng 3 2022
Bài 3:
Số tiền An góp chiếm:
1-1/5-1/5-1/7=16/35(tổng số tiền)
Số tiền quả bóng là:
30500:16/35=66718,75(đồng)
Bài 3:
a) \(\left(-\dfrac{2}{3}\right)^2\cdot\left(\dfrac{2}{3}\right)^5\)
\(=\left(\dfrac{2}{3}\right)^2\cdot\left(\dfrac{2}{3}\right)^5\)
\(=\left(\dfrac{2}{3}\right)^{2+5}\)
\(=\left(\dfrac{2}{3}\right)^7\)
b) \(\left(-\dfrac{1}{2}\right)^5\cdot\left(-\dfrac{1}{2}\right)^3\)
\(=\left(-\dfrac{1}{2}\right)^{5+3}\)
\(=\left(-\dfrac{1}{2}\right)^8\)
\(=\left(\dfrac{1}{2}\right)^8\)
c) \(\left(\dfrac{6}{5}\right)^7\cdot\left(-\dfrac{6}{5}\right)^4\)
\(=\left(\dfrac{6}{5}\right)^7\cdot\left(\dfrac{6}{5}\right)^4\)
\(=\left(\dfrac{6}{5}\right)^{7+4}\)
\(=\left(\dfrac{6}{5}\right)^{11}\)
Bài 4:
a) \(\left(\dfrac{3}{7}\right)^4:\left(-\dfrac{3}{7}\right)^2\)
\(=\left(\dfrac{3}{7}\right)^4\cdot\left(\dfrac{3}{7}\right)^2\)
\(=\left(\dfrac{3}{7}\right)^{4+2}\)
\(=\left(\dfrac{3}{7}\right)^6\)
b) \(\left(\dfrac{5}{9}\right)^{11}:\left(\dfrac{5}{9}\right)^7\)
\(=\left(\dfrac{5}{9}\right)^{11-7}\)
\(=\left(\dfrac{5}{9}\right)^4\)
c) \(\left(\dfrac{2}{13}\right)^7:\left(\dfrac{2}{13}\right)^5\)
\(=\left(\dfrac{2}{13}\right)^{7-5}\)
\(=\left(\dfrac{2}{13}\right)^2\)