a.
(5/11 + 6/11 ) + ( 1/4 +3/4) + ( 6/25 + 9/25)
= 11/11 + 4/4 + 15/25
= 1 +1 + 3/5
= 2+3/5 = 13/5
b.
( 37/100 + 163/100) + (1/8 + 3/8 ) + 19/4 + 1/2
=  200/100 + 4/8 + ( 19/4 + 2/4)
=    2 + 1/2 + 21/4
=  31/4

Bạn tự hỏi rồi từ trả lời ! Bạn xem đầu bạn có nóng không ?

olm ko cho tự hỏi tự trả lời đâu nhoa.

`Answer:`

\(A=\left(1^{100}+2^{100}+...+10^{100}\right)\left(5^{10}-25^5\right)\)

\(=\left(1^{100}+2^{100}+...+10^{100}\right)[5^{10}-\left(5^2\right)^5]\)

\(=\left(1^{100}+2^{100}+...+10^{100}\right)\left(5^{10}-5^{10}\right)\)

\(=\left(1^{100}+2^{100}+...+10^{100}\right).0\)

\(=0\)

\(B=\left(2^5+3^5+4^5\right)\left(1^2+2^2+...+100^2\right)\left(4^{10}-2^{20}\right)\)

\(=\left(2^5+3^5+4^5\right)\left(1^2+2^2+...+100^2\right)\left(2^{2.10}-2^{20}\right)\)

\(=\left(2^5+3^5+4^5\right)\left(1^2+2^2+...+100^2\right).0\)

\(=0\)

\(\dfrac{3}{4}+\dfrac{1}{25}+\dfrac{3}{100}=\dfrac{75}{100}+\dfrac{4}{100}+\dfrac{3}{100}=\dfrac{82}{100}=\dfrac{41}{50}\)
\(\dfrac{1}{20}+\dfrac{3}{4}+\dfrac{6}{5}=\dfrac{1}{20}+\dfrac{15}{20}+\dfrac{24}{20}=\dfrac{40}{20}=2\)

3/4+1/25+3/100 = 41/50

1: \(=\left(217-213+186\right)+\left(-14-49+54\right)\)

\(=190-9=181\)

2: \(=-38\cdot25+38\cdot4-25\cdot4+25\cdot38\)

\(=13\cdot4=52\)

3: \(=-39\cdot5+39\cdot99+99\cdot10-99\cdot39\)

\(=-195+990=795\)

4: =(1+3-5-7)+(9+11-13-15)+...+(393+395-397-399)

=(-8)+(-8)+...+(-8)

=-800

đây là tính nhanh à

tính

\(\frac{3}{5}-\frac{1}{4}\div x=\frac{25}{100}\)

\(\frac{3}{5}-\frac{1}{4}\div x=\frac{1}{4}\)

\(\frac{1}{4}\div x=\frac{3}{5}-\frac{1}{4}\)

\(\frac{1}{4}\div x=\frac{7}{20}\)

\(x=\frac{1}{4}\div\frac{7}{20}\)

\(x=\frac{5}{7}\)

Ta có: 3/5 - 1/4 : x = 25/100

=> 1/4 : x = 3/5 - 25/100

=> 1/4 : x = 7/20

=> x = 1/4 : 7/20

=> x = 5/7

Vậy x = 5/7

\(\frac{3}{5}\)- \(\frac{1}{4}\): x = \(\frac{1}{4}\)
           \(\frac{1}{4}\): x  = \(\frac{3}{5}\)- \(\frac{1}{4}\)
           \(\frac{1}{4}\): x  = \(\frac{7}{20}\)
                      x  = \(\frac{1}{4}\): \(\frac{7}{20}\)
                      x  = \(\frac{1}{4}\)x \(\frac{20}{7}\)
                      x  = \(\frac{5}{7}\)