Tính:
a, \(\frac{37.7+37.3}{74.25-74.10}\)
b,\(\frac{2^{76}-2^{74}}{2^{78}-2^{76}}\)
tinh :\(\frac{2^{76}-2^{74}}{2^{78}-2^{76}}\)
2^76-2^74/2^78-2^76
=2^76-(2^2)^37/(2^2)^38-2^76
=(2^2)^37/(2^2)^38=1/4
tick cho mk nha bạn
Tính
\(_{\frac{2^{76}-2^{74}}{2^{78}-2^{76}}}\)
b)\(\left(1+\frac{1}{11}\right)\left(1+\frac{1}{12}\right).....\left(1+\frac{1}{16}\right)\)
\(\frac{2^{76}-2^{74}}{2^{78}-2^{76}}=\frac{2^{74}\left(2^2-1\right)}{2^{74}\left(2^4-2^2\right)}=\frac{4-1}{16-4}=\frac{1}{4}\)
\(1+\frac{1}{11}=\frac{12}{11}\)
\(1+\frac{1}{12}=\frac{13}{12}\)
\(1+\frac{1}{13}=\frac{14}{13}\)
\(1+\frac{1}{14}=\frac{15}{14}\)
\(1+\frac{1}{15}=\frac{16}{15}\)
\(1+\frac{1}{16}=\frac{17}{16}\)
\(\left(1+\frac{1}{11}\right)\left(1+\frac{1}{12}\right)...\left(1+\frac{1}{16}\right)=\frac{12.13.14.15.16.17}{11.12.13.14.15.16}=\frac{17}{11}\)
2^76-2^74/2^78-2^76
\(\frac{2^{76}-2^{74}}{2^{78}-2^{76}}=\frac{2^{74}\left(2^2-1\right)}{2^{76}\left(2^2-1\right)}=\frac{1}{2^2}=\frac{1}{4}\)
Rút gọn:
\(\dfrac{2^{76}-2^{74}}{2^{78}-2^{76}}\)
\(\dfrac{2^{76}-2^{74}}{2^{78}-2^{76}}=\dfrac{2^{74}\left(2^2-1\right)}{2^{76}\left(2^2-1\right)}=\dfrac{1}{2^2}=\dfrac{1}{4}\)
em quên còn câu này nữa
d,2 mũ 76 - 2 mũ 74 phần 2 mũ 78 - 2 mũ 76
d) Ta có: \(\dfrac{2^{76}-2^{74}}{2^{78}-2^{76}}\)
\(=\dfrac{2^{74}\left(2^2-1\right)}{2^{76}\left(2^2-1\right)}=\dfrac{2^{74}}{2^{76}}\)
\(=\dfrac{1}{2^2}=\dfrac{1}{4}\)
276-274/278-276
276 - 274/278 - 276
= 274 . ( 22 - 1)/276 . ( 22 - 1)
= 274/276
= 1/22 = 1/4
2 mũ 76 trừ 2 mũ 74
2 mũ 78 trừ 2 mũ 76
\(\frac{2^{76}-2^{74}}{2^{78}-2^{76}}=\frac{2^{74}\left(2^2-1\right)}{2^{76}\left(2^2-1\right)}=\frac{2^{74}}{2^{76}}=\frac{1}{2^2}=\frac{1}{4}.\)
học tốt ~~~
Tính:
a) 276-274 / 278-276
b)(1+1/11) (1+1/12) .......(1+1/16)
\(\left(1+\frac{1}{11}\right)\left(1+\frac{1}{12}\right)...\left(1+\frac{1}{16}\right)\)
\(=\frac{12.13.14....17}{11.12.13....16}=\frac{17}{11}\)
\(\frac{74-x}{26}+\frac{75-x}{25}+\frac{76-x}{24}+\frac{77-x}{23}+\frac{78-x}{22}=-5\)
Tìm X
\(\frac{74-x}{26}+\frac{75-x}{25}+\frac{76-x}{24}+\frac{77-x}{23}+\frac{78-x}{22}=-5\)
\(\frac{74-x}{26}+1+\frac{75-x}{25}+1+\frac{76-x}{24}+1+\frac{77-x}{23}+1+\frac{78-x}{22}=-5+5\)
\(\frac{74-x}{26}+\frac{26}{26}+\frac{75-x}{25}+\frac{25}{25}+\frac{76-x}{24}+\frac{24}{24}+\frac{77-x}{23}+\frac{23}{23}+\frac{78-x}{22}+\frac{22}{22}=0\)
\(\frac{100-x}{26}+\frac{100-x}{25}+\frac{100-x}{24}+\frac{100-x}{23}+\frac{100-x}{22}=0\)
\(\left(100-x\right)\left(\frac{1}{26}+\frac{1}{25}+\frac{1}{24}+\frac{1}{23}+\frac{1}{22}\right)=0\)
=>100-x=0 ( \(\left(\frac{1}{26}+\frac{1}{25}+\frac{1}{24}+\frac{1}{23}+\frac{1}{22}\right)\ne0\))
x=100
hahaha
Cộng 1 vào mỗi hạng tử trong vế trái là dc