Tính 

a, 2/13 . 5 - 9/11 . 2/13 - 7/11 . 2/13

b, (-1/2)² + 4,25

c, (-2/3)² : ( --2 2/3) -- ( 5/8 -- 5/6 ) + 5.8--45/5.8

Tính hợp lý:

a) A=\(2021^2\)-2020.(2021+1)

b) B=1+2-3-4+5+6-7-8+9+10-...+2018-2019-2020+2021

c) C=\(\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^9.6^{19}-7.2^{29}.27^6}\)

Thực hiện các phép tính:  

a)A=-4/5:6/5+3/4+1/2-(5/4:1/2)

b)B=2^5.8^4.4^3/16^6+2^3+(1/3)^2+(1/27)^0-3^5.(-25)^2/9^3.5^3

a, tính:\(\frac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^9.6^{19}-7.2^{29}.27^6}\)

b, tìm x biết:\(1\frac{1}{30}:(24\frac{1}{6}-24\frac{1}{5})-\frac{1\frac{1}{2}-\frac{3}{4}}{4x-\frac{1}{2}}=(-1\frac{1}{5}):(8\frac{1}{5}-8\frac{1}{3})\)

rút gọn

5.14 mũ 15.9 mũ 9-4.3 mũ 20.9 mũ 9

_______________________________

5. 2 ,ũ 9.6 mũ 16-7. 2 mũ 29. 27 mũ 6

1. Tìm n thuộcN* biết 1+3+5+...+(2n-1)=225.

2.Tính \(A=\frac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^9.6^{19}-7.2^{29}.27^6}\)

6. tính thuận tiện d) 5,8 + 5.8 x 3 + 5.8 x 5 + 5.8

Tính hợp lý:

A= 21.\(10^2\)-11.100+90.\(10^2\)+\(2^2\).\(5^2\).125.16

B= \(\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^9.6^{19}-7.2^{29}.27^6}\)

C= 3+5-7-9+11+13 -13-17+19+...+2013-2015-2017+2019+2020

tính giá trị:

A=\(\frac{5}{6}-\frac{-1}{12}+\frac{2}{3}-\frac{-2}{7}+\frac{1}{25}-\frac{-1}{4}-\frac{5}{42}\)

B=\(\frac{7.6^{10}.2^{20}.3^6-2^{19}.6^{15}}{9.6^{19}.2^9-4.3^{17}2^{26}}\)