A=2/13.5/9+2/13.4/9+11/13
Tính theo cách hợp lý
a) (10^2+11^2+12^2):(13^2+14^2)
b)1.2.3....9 -1.2.3...8-1.2.3...7.8^2
c)(3.4.2^16)^2 /11.2^13.4^11-16^9
a: \(\dfrac{10^2+11^2+12^2}{13^2+14^2}=\dfrac{100+121+144}{169+196}=\dfrac{365}{365}=1\)
c: \(=\dfrac{3^2\cdot2^{36}}{11\cdot2^{13}\cdot2^{22}-2^{36}}=\dfrac{3^2\cdot2^{36}}{2^{35}\cdot\left(11-2\right)}=2\)
Thuc hien cac phep tinh sau một cách hợp lí:
a) (10^2 + 11^2 + 12^2) : (13^2 + 14^2)
b) 1.2.3...9-1.2.3...8-1.2.3...7.8^2
c) (3.4.2^16)^2/11.2^13.4^11-16^9
d) 1152 - (374 + 1152) +(-65 + 374)
e) 13-12+11+10-9+8-7-6+5-4+3+2-1
a)(10^2+11^2+12^2):(13^2+14^2) b)1.2.3...9-1.2.3...8-1.2.3...7.8^2 c)(3.4.2)^16/11.2^13.4^11-16^9 d)1152-(374+1152)+(-56+374) e)13-12+11+10-9+8-7-6+5-4+3+2-1 |
Bài 1.(1 điểm) Thực hiện phép tính:
a) A= 3/4 + -5/6
b) B= 3/13. 6/11 + 3/13. 9/11-3/13.4/11
gấp giúp em với ạ
-4/13.5/17+-12/13.4/17+4/13
\(-\dfrac{4}{13}.\dfrac{5}{17}+\left(-\dfrac{12}{13}\right).\dfrac{4}{17}+\dfrac{4}{13}.\)
\(=\dfrac{4}{13}.\left(-\dfrac{5}{17}\right)+\left(-\dfrac{12}{17}\right).\dfrac{4}{13}+\dfrac{4}{13}.1\)
\(=\dfrac{4}{13}\left[\left(-\dfrac{5}{17}\right)+\left(-\dfrac{12}{17}\right)+1\right].\)
\(=\dfrac{4}{13}.\left[-1+1\right].\)
\(=\dfrac{4}{13}.0=0.\)
(3*4*2^16)^2 / (11*2^13.4^11-16^9) = ?
Tính:
A= ( 3.4.2^16)^2 / 11.2^13.4^11-16^9
bạn sai rồi
Oh
\(\frac{\left(3.4.2^{16}\right)^2}{11.2^{13}.4^{11}-16^9}\)
\(=\frac{3^2.2^4.2^{32}}{11.2^{13}.2^{22}-2^{36}}\)
\(=\frac{3^2.2^{36}}{11.2^{35}-2^{36}}\)
\(=\frac{3^2.3^{36}}{2^{35}.\left(11-2\right)}\)
\(=\frac{9.2}{9}=2\)
\(A=\frac{\left(3.4.2^{16}\right)^2}{11.2^{13}.4^{11}-16^9}\)
\(A=\frac{3^2.4^2.2^{32}}{11.2^{13}.4^{11}-16^9}\)
\(A=\frac{3^2.2^4.2^{32}}{11.2^{13}.\left(2^2\right)^{11}-\left(2^4\right)^9}\)
\(A=\frac{3^2.2^{36}}{11.2^{13}.2^{22}-2^{36}}\)
\(A=\frac{3^2.2^{36}}{11.2^{35}-2.2^{35}}\)
\(A=\frac{3^2.2^{36}}{\left(11-2\right).2^{35}}\)
\(A=\frac{3^2.2}{9}=\frac{18}{9}=2\)
Tính :
A=(3.4.2^16)^2 / 11.2^13.4^11-16^9
\(A=\frac{\left(3.4.2^{16}\right)^2}{11.2^{13}.4^{11}-16^9}\)
\(=\frac{3^2.4^2.2^{32}}{11.2^{13}.4^{11}-16^9}\)
\(=\frac{3^2.\left(2^2\right)^2.2^{32}}{11.2^{13}.\left(2^2\right)^{11}-\left(2^4\right)^9}\)
\(=\frac{3^2.2^4.2^{32}}{11.2^{13}.2^{22}-2^{36}}\)
\(=\frac{3^2.2^{36}}{11.2^{35}-2^{36}}\)
\(=\frac{3^2.2^{36}}{2^{35}.\left(11-2\right)}\)
\(=\frac{9.2}{2}=2\)
Rút gọn:
A=(3.4.12^16)^2/11.2^13.4^11-16^9