a ) 20 : 22 + 5 9 : 5 8
=( 20 : 4) + ( 5 9 : 5 8 )
= 5 + 5
= 10
b ) 2 x { 198 - [ 158 - 946 + 4 ) x2 ] }
= 2 x { 198 - [ (- 788) +4 ) x 2 ] }
= 2 x { 198 - [ (- 784) x2 ] }
= 2 x { 198 - ( - 1568 ) }
= 2 x 1766
= 3532
c ) 2011 - ( 21 + 314 : 3 12 ) : 15
= 2011 - ( 21 + 9 ) : 15
= 2011 - 30 : 15
= 2011 - 2
= 2005
Tk cho mk nếu đúng sai thì thôi nha . Happy new year 2017
1a) \(20:2^2+5^9:5^8\)
\(=20:4+5\)
\(=5+5\)
\(=5.2\)
\(=10\)
b) \(2.\left\{198-\left[158-946+4\right].2\right\}\)
\(=2.\left\{198-\left(-784\right).2\right\}\)
\(=2.\left\{198-\left(-1568\right)\right\}\)
\(=2.1766\)
\(=3532\)
c) \(2011-\left(21+3^{14}+3^{12}\right):15\)
\(=2011-\left(21+9\right)\)
\(=2011-30\)
\(=1981\)
tk ủng hộ nha
