\(B=\dfrac{2^{10}\cdot3^8-2^{10}\cdot3^{10}}{2^{10}\cdot3^8+2^{10}\cdot3^8\cdot5}=\dfrac{2^{10}\cdot3^8\left(1-3^2\right)}{2^{10}\cdot3^8\left(1+5\right)}=\dfrac{1-9}{6}=\dfrac{-8}{6}=-\dfrac{4}{3}\)
\(E=\frac{4^5.9^4-2.6^9}{2^{10}.3^8+6^8.20}.\frac{5^4.20^4}{25^5.4^5}\)
bài 1 : thực hiện phép tính
1)\(A=\frac{1}{3}-\frac{3}{4}-\left(\frac{-3}{5}\right)+\frac{1}{72}-\frac{2}{9}-\frac{1}{36}+\frac{1}{15}\)
2)\(1-\frac{1}{2}+2-\frac{2}{3}+3-\frac{3}{4}+4-\frac{1}{4}-3-\frac{1}{3}-2-\frac{1}{2}-1\)
3)\(A=\frac{4^5.9^4-2.6^9}{2^{10}.3^8+6^8.20}\)
4)\(\frac{27^2.10^3}{6^2.3^4.4^3}\)
5)\(\frac{11}{125}-\frac{17}{18}-\frac{5}{7}+\frac{4}{9}+\frac{17}{14}\)
giúp mình với
Bài 1:So sánh
a,\(\left(-50\right)^{20}\)và \(2550^{10}\)
b, \(\left(-999\right)^{10}\)và \(999999^5\)
Bài 2:Tìm x thuộc Z để :\(\dfrac{x}{9}\)<\(\dfrac{4}{7}\)<\(\dfrac{x+1}{9}\)
Bài 3:Tìm cặp số nguyên a,b sao cho;
a,\(\dfrac{b}{5}\)+\(\dfrac{1}{10}\)=\(\dfrac{1}{a}\)
b, \(\dfrac{a}{4}\)-\(\dfrac{1}{2}\)=\(\dfrac{3}{b}\)
Bài 4:Rút gọn:
M=\(\dfrac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}-\dfrac{5^{10}.7^3-25^5.49^2}{\left(125:7\right)^9+5^9:\left(14\right)^3}\)
Thuc hien phep tinh;
a/ \(1\dfrac{4}{23}+\dfrac{5}{21}-\dfrac{4}{23}+0,5+\dfrac{16}{21}\)
b/ \(\left(\dfrac{1}{25}+\dfrac{1}{5}+1\right):\left(\dfrac{1}{25}-\dfrac{1}{5}-1\right)\)
c/ \(\dfrac{\dfrac{1}{9}-\dfrac{1}{7}-\dfrac{1}{11}}{\dfrac{4}{9}-\dfrac{4}{7}-\dfrac{4}{11}}\)+ \(\dfrac{0,6-\dfrac{3}{25}-\dfrac{3}{125}-\dfrac{3}{625}}{\dfrac{4}{5}-0,16-\dfrac{4}{125}-\dfrac{4}{625}}\)
d/ \(\dfrac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}-\dfrac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)
Bài 1 :Viết các số sau theo thứ tự từ nhỏ đến lớn \(\left(-2\right)^{100}\),\(3^{57}\),\(\left(-5\right)^{50}\)
Bài 2;Tính xem A gấp mấy lần B:
a,A=3,4.\(10^{-8}\);B=34.\(10^{-9}\)
b,A=\(10^{-4}+10^{-3}+10^{-2}\);B=\(10^{-9}\)
Bài 3:Tìm các số hữu tỉ a,b,c biết:
a,ab=\(\dfrac{3}{5}\);bc=\(\dfrac{4}{5}\);ca=\(\dfrac{3}{4}\)
b,a(a+b+c)=-12 ; b(a+b+c)=18 ; c(a+b+c)=30
c, ab=c ; bc=4.a ; ac=9.b
Tính :
\(E=\dfrac{\left(13\dfrac{1}{4}-2\dfrac{5}{27}-10\dfrac{5}{6}\right).230\dfrac{1}{25}+46\dfrac{3}{4}}{\left(1\dfrac{3}{7}+\dfrac{10}{3}\right):\left(12\dfrac{1}{3}-14\dfrac{2}{7}\right)}\)
a)\(\dfrac{5}{15}+\dfrac{14}{25}-\dfrac{12}{9}+\dfrac{2}{7}+\dfrac{11}{25}\)
b)\(\left(\dfrac{3}{7}-\dfrac{5}{2}-\dfrac{3}{5}\right)-\left(-\dfrac{4}{7}-\dfrac{3}{2}+\dfrac{2}{5}\right)\)
c)\(\left(\dfrac{2}{5}\right)^2+5\dfrac{1}{2}.\left(4,5-2\right)+\dfrac{2^3}{\left(-4\right)}\)
d)\(\left(-\dfrac{1}{2}\right)^2:\dfrac{1}{4}-2.\left(-\dfrac{1}{2}\right)^3\)
e)\(\sqrt{16}.1\dfrac{3}{4}+\dfrac{1}{4}-7\)
f)\(\dfrac{2^9.4^{10}}{8^8}\)
\(\dfrac{x+4}{8}+\dfrac{x+3}{9}=\dfrac{x+2}{10}+\dfrac{x+1}{11}\)
Bài 1 Tính
a) 45^10x5^10/75^10
b ) 2^15.9^4/6^3.8^3
c ) (0.8)^5/(0.4)^6
d ) 8^10+4^10/8^4+4^11
Bài 2 Tìm x
a ) (5x-1).(2x-1/3)=0
b) \(^{2^{x-1}}\)= 16
c ) 3^4<1/9.27^x<3^10
