Bài 44: (SBT/12):
a. (7.35 - 34 + 36) : 34
= (7.35 : 34) + (-34 : 34) + (36 : 34)
= 7 . 3 - 1 + 32
= 21 - 1 + 9
= 29
b. (163 - 642) : 83
= [(2.8)3 - (82)2 ] : 83
= (23 . 83 - 84) : 83
= ( 23 . 83 : 83) + (-84 : 83)
= 23 - 8
= 8 - 8
= 0
a) \(\left(7.3^5-3^4+3^6\right):3^4\)
\(=7.3^5:3^4-3^4:3^4+3^6:3^4\)
\(=7.3^{5-4}-3^{4-4}+3^{6-4}\)
\(=7.3^1-3^0+3^2\)
\(=7.3-1+9\)
\(=21-1+9\)
\(=20+9\)
\(=29\)
b) \(\left(16^3-64^2\right):8^3\)
\(=\left[\left(2^4\right)^3-\left(2^6\right)^2\right]:\left(2^3\right)^3\)
\(=\left(2^{4.3}-2^{6.3}\right):2^{3.3}\)
\(=\left(2^{12}-2^{12}\right):2^9\)
\(=2^{12-9}-2^{12-9}\)
\(=2^3-2^3\)
\(=8-8\)
\(=0\)
