a) \(\frac{399\times45+55\times399}{1995\times1996-1991\times1995}=\frac{399\times\left(45+55\right)}{1995\times\left(1996-1991\right)}=\frac{399\times100}{399\times5\times5}=4\)

b) \(\frac{1996\times1995-996}{1000+1996\times1994}=\frac{1996\times\left(1994+1\right)-996}{1000+1996\times1994}=\frac{1996\times1994+1996-996}{1000+1996\times1994}\)

\(=\frac{1996\times1994+1000}{1000+1996\times1994}=1\)

c) \(\frac{637\times527-189}{526\times637+448}\)bạn làm tương tự ý b).

d) \(\frac{677\times874+251}{678\times874-623}\)bạn làm tương tự ý b). 

= 26% + 9% + 41% + 24%

= 100%

= 1 

= 1 

a: \(=\dfrac{5}{9}\cdot\dfrac{7}{4}+\dfrac{13}{9}\cdot\dfrac{7}{4}=\dfrac{7}{4}\cdot2=\dfrac{7}{2}\)

b: \(=\dfrac{14}{13}\cdot2+\dfrac{3}{13}\cdot2-2\cdot\dfrac{7}{13}=\dfrac{28}{13}+\dfrac{6}{13}-\dfrac{14}{13}=\dfrac{20}{13}\)

cau tra loi thu nhat = 592309

cau tra loi thu hai 592309

k mik nha

a) Số cần tìm là:

677x874+611=592309

b) Số cần tìm là:

678x874-263=592309

Đáp số:592309

677*874+611=592309

678*874-263=592309

(-1)+-39/13