Thực hiện phép tính:
\(\frac{8^{20}+4^{20}}{4^{25}+64^5}\)
Thực hiện phép tính: a) 12.(-5).(-2).(-6);
b) (-4).7.11.(-2)
c) 25.(-5).4.(-20).
d) 125.(-3).(-8).(-10)
a) 12 . ( - 5 ) . ( - 2 ) . ( - 6 )
= - 60 . 12
= - 720
b) ( - 4 ) . 7 . 11 . ( - 2 )
= - 28 . ( - 22 )
= 616
c) 25 . ( - 5 ) . 4 ( - 20 )
= - 125 . ( - 80 )
= 10 000
d) 125 . ( - 3 ) . ( - 8 ) . ( - 10 )
= - 375 . 80
= - 30 000
Thực hiện phép tính: a) 12.(-5).(-2).(-6); b) (-4).7.11.(-2) c) 25.(-5).4.(-20). d) 125.(-3).(-8).(-10)
1) Tìm x
a) (1/4 x X - 1/8) x 3/4 = 1/4
b) 12/5 : X = 14/3 x 4/7
c) x + 2/3 = 8 : 4 - 1
2) Thực hiện phép tính:
a) (1/5 + 3/4) x 1/2
b) 13/20 - (1/4 - 5/20)
c) 1/10 + 4/20 + 9/30 + 25/50 + 36/60 + 49/70 + 64/80 + 81/90
d) 2/3.5 + 2/5.7 + 2/7.9 + ... + 2/41.43
Tính \(M=\frac{8^{20}+4^{20}}{4^{25}+64^5}\)
\(M=\frac{8^{20}+4^{20}}{4^{25}+64^5}\)
\(M=\frac{\left(2^3\right)^{20}+\left(2^2\right)^{20}}{\left(2^2\right)^{25}+\left(2^6\right)^5}\)
\(M=\frac{2^{60}+2^{40}}{2^{50}+2^{30}}\)
\(M=\frac{2^{40}\left(2^{20}+1\right)}{2^{30}\left(2^{20}+1\right)}\)
\(M=2^{10}\)
\(M=1024\)
Thực hiện phép tính :
a) 5^30:(5^25×6+5^25×9)
b) (20×2^4+12×2^4- 48×2^2):8^2
a ) 5 ^30 : ( 5^25 . 6 + 5^25 . 9 )
= 5^30 : [ 5^25 ( 6 + 9 ) ]
= 5^30 : [ 5^25 . 15 ]
= 5^30 : [ 5^25 . 5 . 3 ]
= 5^30 : [ 5^26 . 3 ]
= 5^30 : 5^26 : 3
= 5^4 : 3
b ) ( 20 . 2^4 + 12 . 2^4 - 48 . 2^2 ) : 8^2
= ( 20 . 2^4 + 12.2^4 - 12 . 2^2 . 2^2 ) : 8^2
= ( 20 . 2^4 + 12.2^4 - 12.2^4 ) : 8^2
= 20 . 2^4 : 8^2
= 5 . 2^2 . 2^4 : ( 2^3 )^2
= 5 . 2^6 : 2^6
= 5
= 625 : 3
= 625/3
Lần sau viết đề dễ nhìn chút nhé!Nhìn là thấy không muốn làm rồi.
a) \(5^{30}:\left(5^{25}.6+5^{25}.9\right)\Leftrightarrow5^{30}:\left[5^{25}.\left\{6+9\right\}\right]\)
\(\Leftrightarrow5^{30}:\left[5^{25}.15\right]\)
Bỏ ngoặc đi ta lại có: \(5^{30}:5^{25}.15\)
Theo quy tắt khi phép tính không có ngoặc thì ta làm từ trái sang phải. Ta có:
\(\left(5^{30}:5^{25}\right).15\Leftrightarrow5^{30-25}.15\Leftrightarrow5^5.15\)
\(\Leftrightarrow3125.15=46875\)
b) \(\left(20.2^4+12.2^4-48.2^2\right):8^2\)
\(\Leftrightarrow\left\{\left[2^4.\left(20+12\right)-48.2^2\right]:8^2\right\}\)
\(\Leftrightarrow\left\{\left[2^4.32-48.2^2\right]:8^2\right\}\)
\(\Leftrightarrow\left\{\left[16.32-48.4\right]:64\right\}\)
\(\Leftrightarrow\left\{\left[512-192\right]:64\right\}\Leftrightarrow320:64=5\)
Tính M= \(\frac{8^{20}+4^{20}}{4^{25}+64^5}\)
\(\frac{8^{20}+4^{20}}{4^{25}+64^5}=\frac{\left(2^3\right)^{20}+\left(2^2\right)^{20}}{\left(2^2\right)^{25}+\left(2^6\right)^5}=\frac{2^{60}+2^{40}}{2^{50}+2^{30}}=\frac{2^{40}\times\left(2^{20}+1\right)}{2^{30}\times\left(2^{20}+1\right)}=2^{10}=1024\)
Chúc bạn học tốt ^^
Thực hiện phép tính:
Câu 1:
\(\frac{5^4.18^4}{125.9^5.16}\)
Câu 2:
\(\frac{\left(-5\right)^{32}.20^{43}}{\left(-8\right)^{29}.125^{25}}\)
Câu 1:
\(\frac{5^4.18^4}{125.9^5.16}\) = \(\frac{5^4.\left(2.9\right)^4}{5^3.9^5.2^4}\) = \(\frac{5^4.2^4.9^4}{5^3.9^5.2^4}\) = \(\frac{5}{9}\)
Câu 2:
\(\frac{\left(-5\right)^{32}.20^{43}}{\left(-8\right)^{29}.125^{25}}\) = \(\frac{5^{32}.\left(4.5\right)^{43}}{\left(-2.4\right)^{29}.\left(5^3\right)^{25}}\) = \(\frac{5^{32}.4^{43}.5^{43}}{\left(-2\right)^{29}.4^{29}.5^{75}}\) = \(\frac{4^{14}.5^{43}}{\left(-2\right)^{29}.5^{43}}\)
=\(\frac{4^{14}}{\left(-2\right)^{29}}\) = = \(\frac{\left[-2.\left(-2\right)\right]^{14}}{\left(-2\right)^{29}}\) = \(\frac{\left(-2\right)^{14}.\left(-2\right)^{14}}{\left(-2\right)^{29}}\) = \(\frac{\left(-2\right)^{14}}{\left(-2\right)^{15}}\) = \(\frac{-1}{2}\)
Thực hiện phép tính \(\dfrac{4^5.9^{4^{ }}-2.6^{9^{ }}}{2^{10^{ }}.3^{8^{ }}+6^{8^{ }}.20}:\sqrt{\dfrac{25}{9}}\)
\(\dfrac{4^5.9^4-2.6^9}{2^{10}.3^8+6^8.20}:\sqrt{\dfrac{25}{9}}=\dfrac{2^{10}.3^8-2.2^9.3^9}{2^{10}.3^8+2^8.3^8.2^2.5}:\dfrac{5}{3}\)
\(=\dfrac{2^{10}.3^8-2^{10}.3^9}{2^{10}.3^8+2^{10}.3^8.5}.\dfrac{5}{3}=\dfrac{2^{10}.3^8\left(1-3\right)}{2^{10}.3^8\left(1-5\right)}.\dfrac{5}{3}=\dfrac{1-3}{1-5}.\dfrac{5}{3}=\dfrac{1}{2}.\dfrac{5}{3}=\dfrac{5}{6}\)
\(\dfrac{4^5\cdot9^4-2\cdot6^9}{2^{10}\cdot3^8+6^8\cdot20}\div\sqrt{\dfrac{25}{9}}\)
\(=\dfrac{2^{10}\cdot3^8-2\cdot2^9\cdot3^9}{2^{10}\cdot3^8+2^8\cdot3^8\cdot2^2\cdot5}\div\dfrac{5}{4}\)
=\(\dfrac{2^{10}\cdot3^8\left(1-2\cdot3\right)}{2^{10}\cdot3^8\left(1+5\right)}\div\dfrac{5}{4}\)
=\(\dfrac{1-6}{1+5}\cdot\dfrac{4}{5}\)
=\(-\dfrac{5}{6}\cdot\dfrac{4}{5}\)
=\(-\dfrac{2}{3}\)
Tính :
\(M=\frac{8^{20}+4^{20}}{4^{25}+64^5}\)\(M=\frac{\left(2^3\right)^{20}+\left(2^2\right)^{20}}{\left(2^2\right)^{25}+\left(2^6\right)^5}=\frac{2^{60}+2^{40}}{2^{50}+2^{30}}=\frac{2^{40}\left(2^{20}+1\right)}{2^{30}\left(2^{20}+1\right)}=2^{10}\)
\(M=\frac{8^{20}+4^{20}}{4^{25}+64^5}\)
= \(\frac{\left(2^3\right)^{20}+\left(2^2\right)^{20}}{\left(2^2\right)^{25}+\left(2^6\right)^5}=\frac{2^{60}+2^{40}}{2^{50}+2^{30}}=\frac{2^{40}\left(2^{20}+1\right)}{2^{30}\left(2^{20}+1\right)}=2^{10}\)