6/7.4/11-6/7.15/11+6/7
5a/ A= 4/3.4/7+4/7.4/11+4/11.4/15+...+4/95.4/99
b/ B= 7/2+7/6+7/12+...+7/9900
a thì đặt 4 ra ngoài sau đó tự tính theo cách đã học
câu b tương tự
7.4^5.3^11+2^13.9^5/6^10+2^12.3^10
Rút gọn:
7.4^5.3^11+3^13.9^5/6^10+2^12.3^10
Rút gọn phân số
7.4^5.3^11+2^13.9^5/6^10+2^12.3^10
là bằng 1 nha
ahihihihihihihihihihihihihi
Rút gọn:
7.4^5.3^11+3^13.9^5/6^10+2^12.3^10
Rút gọn phản số sau : 7.4^5.3^11+2^13.9^5/6^10+2^12.3^10
Rút gọn:
3.7.8.13/14.15.26
11.8-11.3/17-6
-17.13+17.2/11.2-11.9
7/9.10^2-2.10^2
7.4^5.3^11+3^13.9^5/6^10+2^12.3^10
2.4+2.4.8+4.8.16+8.16.32/3.4+2.6.8+4.12.16+8.24.32
\(\frac{3.7.8.13}{14\cdot15\cdot26}=\frac{3\cdot7\cdot8\cdot13}{2\cdot7\cdot3\cdot5\cdot2\cdot13}=\frac{8}{5\cdot2\cdot2}=\frac{8}{20}=\frac{2}{5}\)
\(\frac{3.7.8.13}{14.15.26}=\frac{3.7.2^3.13}{2.7.3.5.13.2}=\frac{1.7.2.1}{1.1.1.5.1.1}=\frac{14}{5}\)
\(\frac{11.8-11.3}{17-6}=\frac{11.\left(8-3\right)}{11}=\frac{11.5}{11}=\frac{1.5}{1}=\frac{5}{1}=5\)
\(\frac{-17.13+17.2}{11.2-11.9}=\frac{-17.13+\left(-17\right).2}{11.\left(2-9\right)}=\frac{-17.\left(-13+2\right)}{11.\left(-7\right)}=\frac{-17.\left(-11\right)}{11.\left(-7\right)}=\frac{-17.\left(-1\right)}{-1.\left(-7\right)}=\frac{17}{7}\)
\(\frac{7}{9.10^2-2.10^2}=\frac{7}{100\left(9-2\right)}=\frac{7}{100.7}=\frac{7}{700}=\frac{1}{100}\)
mình làm được tới đó thôi, hihi.
Co ai biết lam con thu 5 ko, giúp minh voi. Dang mai minh nộp bai roi
1) Thực hiện phép tính
a) 78 - 12.5 + 32
b) 42 . 55 + 2 . 45 . 8 - 20240
c) 1800 : {49 - [ 2.(62 -34)3 - 54 : 53]}
d)\(\dfrac{15.2^{11}.3^{10}-6^{11}}{12.6^{10}+7.4^6.9^6}\)
2) Tìm x biết
27 : 3x + 31 = 2.52 - 42
Giải gấp cho em với ạ
2:
=>27:3^x=2*25-16-31=50-47=3
=>3^x=27/3=9
=>3^x=3^2
=>x=2
1:
b: \(=16\cdot55+16\cdot45-1\)
=16(55+45)-1
=1600-1
=1599
c: \(=\dfrac{1800}{49-\left[2\cdot\left(36-34\right)^3-5\right]}\)
\(=\dfrac{1800}{49-2\cdot2^3+5}=\dfrac{1800}{49-16+5}=\dfrac{1800}{38}\)=900/19
d: \(=\dfrac{5\cdot3^{11}\cdot2^{11}-3^{11}\cdot2^{11}}{2^{10}\cdot3^{10}\cdot2^2\cdot3+7\cdot2^{12}\cdot3^{12}}\)
\(=\dfrac{3^{11}\cdot2^{11}\left(5-1\right)}{2^{12}\cdot3^{11}\left(1+7\cdot3\right)}=\dfrac{1}{2}\cdot\dfrac{4}{1+21}=\dfrac{4}{22\cdot2}=\dfrac{1}{11}\)
Rút gọn phân số:\(\frac{7.4^5.3^{11}+2^{13}.9^5}{6^{10}+2^{12}.3^{10}}\)