3.6+3/4
1+1.2+3-3.6-4=?
1 + 1 x 2 + 3 - 3 x 6 - 4
= 1 + 2 + 3 - 18 - 4
= -16
k nha
\(1+1.2+3-3.6-4\)
\(=1+2+3-18-4\)
\(=6-18-4\)
\(=-12-4=-16\)
2.4*3+1.8*4+1.2*6+3.6*2+14.4+7.2*4
tính
a) A = \(\dfrac{6^3+3.6^2+3^3}{-13}\)
b) B =\(\dfrac{2.8^4.27^2+4.6^9}{2^3.6^7+2^7.40.9^4}\)
c) C=\(\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^{16}.6^{19}-7.2^{29}.27^6}\)
a: \(A=\dfrac{3^3\cdot2^3+3^3\cdot2^2+3^3\cdot1}{-13}=\dfrac{27\left(2^3+2^2+1\right)}{-13}=-27\)
b: \(B=\dfrac{2\cdot2^{12}\cdot3^6+2^{11}\cdot3^9}{2^3\cdot2^7\cdot3^7+2^7\cdot2^3\cdot5\cdot3^8}\)
\(=\dfrac{2^{13}\cdot3^6+2^{11}\cdot3^9}{2^{10}\cdot3^7+2^{10}\cdot5\cdot3^8}\)
\(=\dfrac{2^{11}\cdot3^6\left(2^2+3^3\right)}{2^{10}\cdot3^7\left(1+5\cdot3\right)}=\dfrac{2}{3}\cdot\dfrac{4+27}{1+15}=\dfrac{2}{3}\cdot\dfrac{31}{16}=\dfrac{31}{24}\)
c: \(C=\dfrac{5\cdot2^{30}\cdot3^{18}-2^{29}\cdot3^{20}}{5\cdot2^{35}\cdot3^{19}-7\cdot2^{29}\cdot3^{18}}\)
\(=\dfrac{2^{29}\cdot3^{18}\left(5\cdot2-3^2\right)}{2^{29}\cdot3^{18}\left(5\cdot2^6-7\right)}=\dfrac{10-9}{5\cdot64-7}=\dfrac{1}{313}\)
Cho Mình hỏi câu này : C = 1.4 + 2.5 + 3.6 + 4.7 + … + n(n + 3)
Mình thấy trên mạng các bạn làm ntn "Ta thấy: 1.4 = 1.(1 + 3)
2.5 = 2.(2 + 3)
3.6 = 3.(3 + 3)
4.7 = 4.(4 + 3)
…….
n(n + 3) = n(n + 1) + 2n
Vậy C = 1.2 + 2.1 + 2.3 + 2.2 + 3.4 + 2.3 + … + n(n + 1) +2n "
Vấn đề mình không hiểu ở đây là 3.6 =3.(3+3) Vứt đi đâu rồi =,=
3 . 6 = 3 . 4 + 2 . 3 rùi đấy bạn, bn xét từng tích rùi sẽ thấy thôi.
Sorano Yuuki !!! Mình hiểu rồi . Thì ra người ta tách sai =.= Cảm ơn nhé .
Đáng nhẽ là . Ta thấy 1.4=1.(2+2)
2.5 = 2.(2 + 3)
3.6 = 3.(2 + 4)
4.7 = 4.(2 + 5)
……
n(n + 3) = n(n + 1) + 2
\(\frac{2^3.6^4-4^4.3^5}{2^{10}.3^4}\)
\(\frac{2^3.6^4-4^4.3^5}{2^{10}.3^4}=\frac{2^3.\left(2.3\right)^4-\left(2^2\right)^4.3^5}{2^{10}.3^4}=\frac{2^3.2^4.3^4-2^8.3^5}{2^{10}.3^4}=\frac{2^7.3^4-2^8.3^5}{2^{10}.3^4}=\frac{2^7.3^4.\left(1-2.3\right)}{2^{10}.3^4}\)
\(=\frac{1-8}{2.3}=\frac{-7}{8}\)
a) \(\dfrac{6^3+3.6^2+3^3}{-13}\)
b) \(\dfrac{5^4.20^4}{24^5.4^5}\)
1/3.(4/5)-1/3.6/5+2/3
BÀI 2 TÍNH :
A = \(\dfrac{6^3+3.6^2+3^3}{13}\)
B = \(\dfrac{4^6.9^5+6^9.120}{8^4-3^{12}.6^{11}}\)
\(A=\dfrac{6^3+3\cdot6^2+3^3}{13}\)
\(=\dfrac{3^3\cdot8+3^3\cdot4+3^3}{13}\)
=27
dấu chấm là nhân, giúp gấp ạ
1/4. 7/3.12
3/8.56.25/7. (-4)
3/7.2/5.7/3.20.19/72
1/3.4/5+1/3.6/5
a: \(=\dfrac{7}{12}\cdot12=7\)
b: \(=\dfrac{3}{8}\cdot\dfrac{25}{7}\cdot56\cdot\left(-4\right)=-300\)
c: \(=\dfrac{3}{7}\cdot\dfrac{7}{3}\cdot\dfrac{2}{5}\cdot20\cdot\dfrac{19}{72}=8\cdot\dfrac{19}{72}=\dfrac{19}{9}\)
d: \(=\dfrac{1}{3}\left(\dfrac{4}{5}+\dfrac{6}{5}\right)=\dfrac{2}{3}\)