tính nhanh
a, -4.2.6.25.<-7>.25
b, 47.69-31.<-47>
c, 19.25+9.95+38.15
d,<-32>.125.<-9>.<-25>
e, <-3879-3879-3879-3879>.<-25>
g, 369.<-2>-41.72
h, 16.<38-2>-38.<16-1>
i, <-41>–<59+2>+59<41-2>
Làm ơn giúp mình với mai mình nộp rồi ai làm đc hết mình tick cho
k, <-1>mũ 19
l, <-1> mũ 2002
m, <-2> mũ 5
Đáp án:
Giải thích các bước giải:
a. – 4 . 2 . 6 . 25 . ( – 7 ) . 25
= [ ( – 4 ) . 25 ] . ( 2 . 25 ) . [ 6 . ( – 7 ) ]
= ( – 100 ) . 50 . ( – 42 )
= ( – 5000 ) . ( – 42 )
= 210000
b. 47 . 69 – 31 . ( – 47 )
= 47 . 69 – ( – 31 ) . 47
= 47 . [ 69 – ( – 31 )]
= 47 . ( 69 + 31 )
= 47 . 100
= 4700
e, ( – 3879 – 3879 – 3879 – 3879 ) . ( – 25 )
= 3879 . ( – 4 ) . ( -25 )
= 3879 . [ ( – 4 ) . ( – 25 ) ]
= 3879 . 100
= 387900
h, 16 . ( 38 – 2 ) – 38 . ( 16 – 1 )
= 16 . 38 – 16 . 2 – 38 . 16 + 38
= 38 – 16 .2
= 38 – 32
= 6
k, ( – 1 ) mũ 19 = – 1
l, ( – 1 ) mũ 2002 = 1
m, ( – 2 ) mũ 5 = – 10
$\begin{array}{l}
a)\,\, – 4.2.6.25.\left( { – 7} \right).25\\
= 2.6.25.\left( { – 7} \right).\left[ {\left( { – 4} \right).25} \right]\\
= – 2100.\left( { – 100} \right)\\
= 210000\\
b)\,\,47.69 – 31.\left( { – 47} \right)\\
= 47.69 – 31.\left( { – 1} \right).47\\
= 47.69 + 31.47\\
= 47.\left( {69 + 31} \right)\\
= 47.100\\
= 4700\\
c)\,\,19.25 + 9.95 + 38.15\\
= 19.25 + 9.5.19 + 19.2.15\\
= 19.25 + 19.45 + 19.30\\
= 19.\left( {25 + 45 + 30} \right)\\
= 19.100\\
= 1900\\
d)\,\,\left( { – 32} \right).125.\left( { – 9} \right).\left( { – 25} \right)\\
= 4.\left( { – 8} \right).125.\left( { – 9} \right).\left( { – 25} \right)\\
= \left[ {4.\left( { – 25} \right)} \right].\left[ {\left( { – 8} \right).125} \right].\left( { – 9} \right)\\
= – 100.\left( { – 1000} \right).\left( { – 9} \right)\\
= 100000.\left( { – 9} \right)\\
= – 900000
\end{array}$