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Ta có 23 số hạng 19 và 19 số hạng 77
=>19.23+19.77
=19.(23+77)
=19.100=1900
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− 123 + 77 + − 257 + 23 − 43 = − 123 + 23 + − 43 + − 257 + 77 = − 100 + − 300 + 77 = − 400 + 77 = − 323.
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d) ( - 15 ) - 23 + ( - 85 ) - 77
= ( - 15 - 85 ) - ( 23 + 77 )
= - 100 - 100
= - 200
e) ( 123 - 37 ) - 123
= ( 123 - 123 ) - 37
= 0 - 37
= - 37
f) ( - 224 ) - ( 34 - 224 )
= ( - 224 + 224 ) - 34
= 0 - 34
= - 34
g) 126 - ( 126 - 33 )
= ( 126 - 126 ) - 33
= 0 - 33
= - 33
h) ( - 53 - 23 ) - ( 567 - 53 )
= ( - 53 + 53 ) + ( - 23 - 567 )
= 0 - 590
= - 590
d) ( - 15 ) - 23 + ( - 85 ) - 77
= ( - 15 - 85 ) - ( 23 + 77 )
= - 100 - 100
= - 200
e) ( 123 - 37 ) - 123
= ( 123 - 123 ) - 37
= 0 - 37
= - 37
f) ( - 224 ) - ( 34 - 224 )
= ( - 224 + 224 ) - 34
= 0 - 34
= - 34
g) 126 - ( 126 - 33 )
= ( 126 - 126 ) - 33
= 0 - 33
= - 33
h) ( - 53 - 23 ) - ( 567 - 53 )
= ( - 53 + 53 ) + ( - 23 - 567 )
= 0 - 590
= - 590
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\(\left(2^{17}+7^2\right).\left(9^{15}-3^{15}\right).\left(2^4-4^2\right)\)
\(=\left(2^{17}+7^2\right).\left(9^{15}-3^{15}\right).\left(16-16\right)\)
\(=\left(2^{17}+7^2\right).\left(9^{15}-3^{15}\right).0\)
\(=0\)
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\(\left(7^{1997}-7^{1995}\right):\left(7^{1994}.7\right)\)
\(=\left[7^{1995}\left(7^2-1\right)\right]:7^{1995}\)
\(=7^{1995}.48:7^{1995}\)
\(=48\)
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\(\left(1^2+2^3+3^4+4^5\right).\left(1^3+2^3+3^3+4^3\right).\left(3^8-81^2\right)\)
\(=\left(1^2+2^3+3^4+4^5\right).\left(1^3+2^3+3^3+4^3\right).\left(6561-6561\right)\)
\(=\left(1^2+2^3+3^4+4^5\right).\left(1^3+2^3+3^3+4^3\right).0\)
\(=0\)
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\(\left(2^8+8^3\right):\left(2^5.2^3\right)\)
\(=\left[2^8+\left(2^3\right)^3\right]:2^8\)
\(=\left(2^8+2^9\right):2^8\)
\(=2^8.\left(1+2\right):2^8\)
\(=2^8.3:2^8\)
\(=3\)
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a, 2 17 + 17 2 9 15 - 3 15 2 4 - 4 2
= 2 17 + 17 2 9 15 - 3 15 16 - 16
= 2 17 + 17 2 9 15 - 3 15 . 0
= 0
b, 1 2 + 2 3 + 3 4 + 4 5 . ( 1 3 + 2 3 + 3 3 + 4 3 ) ( 3 8 - 81 2 )
= 1 2 + 2 3 + 3 4 + 4 5 . ( 1 3 + 2 3 + 3 3 + 4 3 ) ( 3 4 . 2 - 81 2 )
= 1 2 + 2 3 + 3 4 + 4 5 . ( 1 3 + 2 3 + 3 3 + 4 3 ) ( 81 2 - 81 2 )
= 1 2 + 2 3 + 3 4 + 4 5 . ( 1 3 + 2 3 + 3 3 + 4 3 ) . 0
= 0
c, 7 24 + 7 23 : 7 22
= 7 24 : 7 22 + 7 23 : 7 22
= 7 24 - 22 + 7 23 - 22
= 7 2 + 7 1
= 49 + 7 = 56