Tính bằng cách hợp lí:
\(\frac{2^7.9^2}{3^3.2^5}\)
Tính bằng cách hợp lí :
a , \(4\frac{3}{4}+\left(-0,37\right)+\frac{1}{8}+\left(-1,28\right)+\left(-2,5\right)+3\frac{1}{2}\)
b ,\(\frac{3}{5.7}+\frac{3}{7.9}+...+\frac{3}{59\cdot61}\)
c,\(\frac{\frac{5}{22}+\frac{3}{13}-\frac{1}{2}}{\frac{4}{13}-\frac{2}{11}+\frac{3}{2}}\)
Tính theo cách hợp lí :
\(4.5^2-3.2^3+6^5:6^3\)
4.52-3.23+65:63
=4.25-3.8+62
=4.25-3.2.4+36
=4.(25-3.2)+36
=4.19+36
=76+36
=112
4.5^2-3.2^3+6^5:6^3
=4.25-3.8+6^3
=100-24+216
=76+216
=292
\(\frac{2^7.9^2}{3^3.2^5}\)
\(\frac{2^7.9^2}{3^3.2^5}=\frac{2^7.\left(3^2\right)^2}{3^3.2^5}=\frac{2^7.3^4}{3^3.2^5}=2^2.3=12\)
Có gì sai sót thì bỏ qua nhé chị !
Ta có : \(\frac{2^7.9^2}{3^3.2^5}=\frac{2^5.2^2.81}{27.2^5}=\frac{2^5.2^2.27.3}{27.2^5}=2^2.3=12\)
Vậy \(\frac{2^7.9^2}{3^3.2^5}=12\)
\(\frac{2^7\cdot9^2}{3^3\cdot2^5}=\frac{2^7\cdot\left(3^2\right)^2}{3^3\cdot2^5}=\frac{2^7\cdot3^4}{3^3\cdot2^5}=2^2\cdot3=4\cdot3=12\)
tính theo cách hợp lí
a) \(\frac{3}{1.3}+\frac{3}{3.5}+.....+\frac{3}{49.51}\)
b) \(\frac{1}{2}-\frac{1}{2016.2015}-\frac{1}{2015.2014}-....-\frac{1}{3.2}\)
thực hiện phép tính:
\(\frac{2^7.9^2}{3^3.2^5}\)
\(\frac{2^7.9^2}{3^3.2^5}=\frac{2^7.3^4}{3^3.2^5}=\frac{2^2.3}{1.1}=12\)
\(\frac{2^7.9^2}{3^3.2^5}\)
\(=\frac{2^{5+2}.\left(3^2\right)^2}{3^3.2^5}\)
\(=\frac{2^5.2^2.3^4}{3^3.2^5}\)
\(=2^2.3\)
\(=4.3\)
\(=12\)
^_^
\(\frac{2^7\cdot9^2}{3^3\cdot2^5}\)
⇒\(\frac{2^7\cdot\left(3^2\right)^2}{3^3\cdot2^5}\)
⇒\(\frac{2^7\cdot3^4}{3^3\cdot2^5}\)
⇒\(2^2\cdot2\)
⇒\(4\cdot2\)
➩\(8\)
Chúc bạn học tốt nhé Thuong Hoai!
tính bằng cách hợp lí :
\(\left(6-\frac{2}{3}+\frac{1}{2}\right)-\left(5+\frac{5}{3}-\frac{3}{2}\right)-\left(3-\frac{7}{3}+\frac{5}{2}\right)\)
\(\left(6-\frac{2}{3}+\frac{1}{2}\right)-\left(5+\frac{5}{3}-\frac{3}{2}\right)-\left(3-\frac{7}{3}+\frac{5}{2}\right)\)
\(=6-\frac{2}{3}+\frac{1}{2}-5-\frac{5}{3}+\frac{3}{2}-3+\frac{7}{3}-\frac{5}{2}\)
\(=\left(6-5-3\right)-\left(\frac{2}{3}+\frac{5}{3}-\frac{7}{3}\right)+\left(\frac{1}{2}-\frac{3}{2}+\frac{5}{2}\right)\)
\(=-2-1+\frac{3}{2}\)
= \(-3+\frac{3}{2}\)
\(=-\frac{3}{2}\)
TÍNH BẰNG CÁCH HỢP LÍ NHẤT
\(\frac{5}{3}+\left(\frac{-2}{7}\right)-\left(-1,2\right)\)
\(\frac{5}{3}+\left(-\frac{2}{7}\right)-\left(-1.2\right)\)
\(=\frac{5}{3}+\left(-\frac{2}{7}\right)+1.2\)
\(=\frac{271}{105}\)
tíc mình nha
2^7.9^2/3^3.2^5
\(\frac{2^7.9^2}{3^3.2^5}\)\(=\frac{2^7.\left(3^2\right)^2}{3^3.2^5}=\frac{2^7.3^4}{3^3.2^5}=\frac{2^2.3}{1}=2^2.3=4.3=12\)
Tính hợp lí
a) 3/5.7 + 3/7.9 +.....+ 3/59.61
b) 5/22 + 3/13 - 1/2 / 4/13 - 2/11+ 3/2
mn gúp hộ em với
a) Ta có: \(\dfrac{3}{5\cdot7}+\dfrac{3}{7\cdot9}+...+\dfrac{3}{59\cdot61}\)
\(=\dfrac{3}{2}\left(\dfrac{2}{5\cdot7}+\dfrac{2}{7\cdot9}+...+\dfrac{2}{59\cdot61}\right)\)
\(=\dfrac{3}{2}\left(\dfrac{1}{5}-\dfrac{1}{61}\right)\)
\(=\dfrac{3}{2}\cdot\dfrac{56}{305}=\dfrac{84}{305}\)
a)
3/5.7+3/7.9+...+3/59.61
=3/2.(2/5.7+2/7.9+...+2/59.61)
=3/2.(1/5−1/7+1/7−1/9+...+1/59−1/61)
=3/2(1/5−1/61)
=3/2.56/305
=844/305
b) câu b, bạn vt hơi khó hiểu