tinh N = \(\frac{5.\left(2^2.3^2\right)^9.\left(2^2\right)^6-2.\left(2^2.3\right)^{14}.3^6}{5.2^{28}.3^{19}-7.2^{29}.3^{18}}\)
Cho a ;b la cac so nguyen thoa man (\(a^2+b^2\)) chia hết cho 3 . CM a và b cùng chia hết cho 3.
tính N = \(\frac{5.\left(2^2.3^2\right)^9.\left(2^2\right)^6-2.\left(2^2.3\right)^{14}.3^6}{5.2^{28}.3^{19}-7.2^{29}.3^{18}}\)
Ta có : N = \(\frac{5.\left(2^3.3^2\right)^9.\left(2^2\right)^6-2.\left(2^2.3\right)^{14}.3^6}{5.^{28}.3^{19}-7.2^{29}.3^{18}}\)
= \(\frac{5.2^{18}.3^{18}.2^{12}-2.2^{28}.3^{14}.3^4}{2^{28}.3^{18}.\left(5-7.2\right)}\)
= \(\frac{5.2^{30}.3^{18}-2^{29}.3^{18}}{2^{28}.3^{18}.\left(-9\right)}\)
= \(\frac{3^{18}.2^{29}.\left(10-1\right)}{2^{28}.3^{18}.\left(-9\right)}=-2\)
Vậy N = -2
\(\frac{5.\left(2^2.3^2\right)^9.\left(2^2\right)^6-2.\left(2^2.3\right)^{14}.3^6}{5.2^{28}.3^{19}-7.2^{29}.3^{18}}\)
Tính N = \(\frac{5.\left(2^2.3^2\right)^9.\left(2^2\right)^6-2.\left(2^2.3\right)^{14}.3^6}{5.2^{28}.3^{19}-7.2^{29}.3^{18}}\)
\(N=\frac{5.2^{18}.3^{18}.2^{12}-2.2^{28}.3^{14}.3^6}{5.2^{28}.3^{19}-7.2^{29}.3^{18}}\)
\(N=\frac{5.2^{30}.3^{18}-2^{29}.3^{20}}{5.2^{28}.3^{19}-7.2^{29}.3^{18}}\)
\(N=\frac{2^{28}.3^{18}\left(5.2^2-2.3^2\right)}{2^{28}.3^{18}\left(5.3-7.2\right)}\)
\(N=\frac{5.4-2.9}{5.3-7.2}=\frac{20-18}{15-14}=2\)
Vậy N = 2
\(\frac{5.\left(2^2.3^2\right)^9.\left(2^2\right)^6-2.\left(2^2.3\right)^{14}.3^6}{5.2^{28}.3^{19}-7.2^{29}.3^{18}}\)tính nhanh
Tính N = \(\frac{5.\left(2^3.3^2\right)^9.\left(2^2\right)^6-2.\left(2^2.3\right)^{14}.3^6}{5.2^{28}.3^{19}-7.2^{29}.3^{18}}\)
Thực hiện phép tinh
A = \(\frac{5.\left(2^2.3^2\right)^9.\left(2^2\right)^6-2\left(2^2.3\right)^{14}.3^4}{5.2^{28}.3^{18}-7.2^{29}.3^{18}}\)
A = \(\frac{5.\left(2^2.3^2\right)^6.\left(2^2\right)^6-2\left(2^2.3\right)^{14}.3^4}{5.2^{28}.3^{18}-7.2^{29}.3^{18}}\)
= \(\frac{5.2^{18}.3^{18}.2^{12}-2.2^{28}.3^{14}.3^4}{5.2^{28}.3^{18}-7.2.2^{28}.3^{18}}\)
= \(\frac{5.2^{29}.2.3^{18}-2^{29}.3^{18}}{\left(5-14\right).2^{28}.3^{18}}\)
= \(\frac{\left(10-1\right).2^{29}.3^{18}}{\left(5-14\right).2^{28}.3^{18}}\)
= \(\frac{9.2}{-9}\)
= \(-2\)
\(A=\frac{5\cdot\left(2^2\cdot3^2\right)^9\cdot\left(2^2\right)^6-2\left(2^2\cdot3\right)^{14}\cdot3^4}{5\cdot2^{28}\cdot3^{18}-7\cdot2^{29}\cdot3^{18}}\)
\(\Rightarrow A=\frac{5\cdot2^{18}\cdot3^{18}\cdot2^{12}-2\cdot2^{28}\cdot3^{14}\cdot3^4}{5\cdot2^{28}\cdot3^{18}-7\cdot2^{28}\cdot2\cdot3^{18}}\)
\(\Rightarrow A=\frac{5\cdot2^{30}\cdot3^{18}-2\cdot2^{28}\cdot3^{18}}{5\cdot2^{28}\cdot3^{18}-14\cdot2^{28}\cdot3^{18}}\)
\(\Rightarrow A=\frac{5\cdot2^{28}\cdot2^2\cdot3^{18}-2\cdot2^{28}\cdot3^{18}}{5\cdot2^{28}\cdot3^{18}-14\cdot2^{28}\cdot3^{18}}\)
\(\Rightarrow A=\frac{20\cdot2^{28}\cdot3^{18}-2\cdot2^{28}\cdot3^{18}}{5\cdot2^{28}\cdot3^{18}-14\cdot2^{28}\cdot3^{18}}\)
\(\Rightarrow A=\frac{2^{28}\cdot3^{18}\cdot\left(20-2\right)}{2^{28}\cdot3^{18}\left(5-14\right)}\)
\(\Rightarrow A=\frac{18}{-9}=-2\)
A=\(\frac{5.\left(2^2.3^2\right)^9.\left(2^2\right)^6-2.\left(2^2.3\right)^{14}.3^4}{5.2^{28}.3^{18}-7.2^{29}.3^{18}}\)
\(A=\frac{5.2^{18}.3^{18}.2^{12}-2.2^{28}.3^{14}.3^4}{5.2^{28}.3^{18}-7.2^{29}.3^{18}}\)
\(A=\frac{5.2^{30}.3^{18}-2^{29}.3^{18}}{5.2^{28}.3^{18}-7.2^{29}.3^{18}}\)
\(A=\frac{2^2\left(5.2^{28}.3^{18}\right)-2^{29}.3^{18}}{5.2^{28}.3^{18}-7.2^{29}.3^{18}}\)
\(A=\frac{2^2-1}{1-7}\)
\(A=\frac{3}{-6}=\frac{1}{-2}=-\frac{1}{2}\)
bài này ư hơi dễ đó nhìn sơ qua là biết
\(\frac{5.\left(2^2.3^2\right)^9\left(2^2\right)^6-2. \left(2^2.3\right)^{14}.3^4}{5.2^{28}.3^{18}-7.2^{29}.3^{18}}\)
\(\frac{5.\left(2^2.3^2\right)^9\left(2^2\right)^6-2.\left(2^2.3\right)14.3^{ }^4}{22}\)
A=\(\frac{5.\left(2^2.3^2\right)^9.\left(2^2\right)^6-2.\left(2^2.3\right)^{14}.3^4}{5.2^{28}.3^{18}-7.2^{29}.3^{18}}\)
Tính A
\(A=\frac{5.\left(2^2.3^2\right)^9.\left(2^2\right)^6-2.\left(2^2.3\right)^{14}.3^{14}}{5.2^{28}.3^{18}-7.2^{29}.3^{18}}\)
\(A=\frac{5.\left(2^2\right)^9.\left(3^2\right)^9.\left(2^2\right)^6-2.\left(2^2\right)^{14}.3^{14}.3^4}{5.2^{28}.3^{18}-7.2^{29}.3^{18}}\)
\(A=\frac{5.2^{18}.3^{18}.2^{12}-2.2^{28}.3^{18}}{5.2^{28}.3^{18}-7.2.2^{28}.3^{18}}\)
\(A=5.\frac{\left(2^{18}.2^{12}\right).3^{18}.2^{29}.3^{18}}{2^{28}.3^{18}.\left(5-7-2\right)}\)
\(A=\frac{5.2^{30}.3^{18}-2^{29}.3^{18}}{2^{28}.3^{18}.\left(-9\right)}\)
\(A=\frac{5.2.2^{29}.3^{18}-2^{29}.3^{18}}{2^{28}.3^{18}.\left(-9\right)}\)
\(A=\frac{2^{20}.2^{18}.\left(5.2-1\right)}{2^{28}.3^{18}.\left(-9\right)}\)
\(A=\frac{2^{29}.3^{18}.9}{2^{28}.3^{18}.\left(-9\right)}\)
\(A=\frac{2.11}{11.\left(-2\right)}\)
\(A=-2\)
Vậy : A = -2
Tính :
\(B\)\(=\frac{5.\left(2^2.3^2\right)^9.\left(2^2\right)^6-2.\left(2^2.3\right)^{14}.3^6}{5.2^{28}.3^{19}-7.2^{29}.3^{18}}\)