\(a,5\frac{1}{4}+3,25-50\%+y=15,25\)

\(\Leftrightarrow5,25+3,25-\frac{50}{100}+y=15,25\)

\(\Leftrightarrow5,25+3,25-0,5+y=15,25\)

\(\Leftrightarrow8+y=15,25\)

\(\Leftrightarrow y=15,25-8=7,25\)

\(b,(y-3):2=2010\)

\(\Leftrightarrow y-3=4020\)

\(\Leftrightarrow y=4023\)

\(c,\frac{7+y}{33}=\frac{9}{11}\)

\(\Leftrightarrow7+y=\frac{9}{11}\cdot33\)

\(\Leftrightarrow7+y=\frac{9}{1}\cdot3\)

\(\Leftrightarrow7+y=27\Leftrightarrow y=20\)

\(\dfrac{11}{49}\times\dfrac{9}{1}\times\dfrac{7}{33}=\dfrac{11\times9\times7}{7\times7\times1\times11\times3}=\dfrac{9}{21}=\dfrac{3}{7}\)

3/7 nha

\(A=\frac{10}{5.7}+\frac{10}{7.9}+\frac{10}{9.11}+...+\frac{10}{33.35}\)

\(\Rightarrow A=10.\left(\frac{1}{5.7}+\frac{1}{7.9}+\frac{1}{9.11}+...+\frac{1}{33.35}\right)\)

Đặt \(B=\frac{1}{5.7}+\frac{1}{7.9}+\frac{1}{9.11}+...+\frac{1}{33.35}\)

\(\Rightarrow2B=\frac{2}{5.7}+\frac{2}{7.9}+\frac{2}{9.11}+...+\frac{2}{33.35}\)

\(\Rightarrow2B=\frac{1}{5}-\frac{1}{35}=\frac{6}{35}\)

\(\Rightarrow B=\frac{3}{35}\)

\(\Rightarrow A=10.\frac{3}{35}=\frac{30}{35}=\frac{6}{7}\)

_Học tốt_

6/7 nha .Tính mãi mới ra

Thank you bạn nha .Bạn kết bạn với mình nhé,mình cũng là fan của BTS

A=(\(\dfrac{1}{3}-\dfrac{1}{3}\))\(+\left(\dfrac{3}{5}+\left(\dfrac{-3}{5}\right)\right)+\left(\dfrac{-5}{7}+\dfrac{5}{7}\right)+\left(\dfrac{-7}{9}+\dfrac{7}{9}\right)\)\(+\left(\dfrac{-11}{13}-\dfrac{9}{11}\right)\)

A\(=0+0+0+0+\dfrac{-238}{143}\)

A\(=\dfrac{-238}{143}\)

\(B=\left(1+\dfrac{1}{2}\right)+\left(1+\dfrac{1}{4}\right)+\left(1+\dfrac{1}{8}\right)+\left(1+\dfrac{1}{32}\right)+\left(1+\dfrac{1}{64}\right)-7\)

\(B=\left(1+1+1+1+1\right)+\left(\dfrac{1}{2}+\dfrac{1}{4}+\dfrac{1}{8}+\dfrac{1}{16}+\dfrac{1}{32}+\dfrac{1}{64}\right)-7\)

\(B=6+\dfrac{63}{64}-7\)

\(B=-1+\dfrac{63}{64}\)

\(B=\dfrac{-1}{64}\)

\(\Leftrightarrow\left(11+\dfrac{7}{18}-9-\dfrac{13}{18}\right):x=\dfrac{5}{3}+\dfrac{35}{33}\cdot\dfrac{11}{7}=\dfrac{10}{3}\)

\(\Leftrightarrow x=\dfrac{5}{3}:\dfrac{10}{3}=\dfrac{1}{2}\)

485 phút, 4 giờ 18 phút, 32/7, 7/24, 9/4, 10

a) 2/3 + 3/4 . (-4/9)

= 2/3 - 1/3

= 1/3

b) -5/7 . 31/33 + (-5/7) : 33/2

= -5/7 . 31/33 - 5/7 . 2/33

= -5/7 . (31/33 + 2/33)

= -5/7 . 1

= -5/7

c) -3/5 . 13/11 - (-3/5) . 2/11

= -3/5 . (13/11 - 2/11)

= -3/5 . 1

= -3/5

wow! mù mắt. Ido tính toán có khác!

C2:(32+1)x32:2=528

bạn tính thử xem đúng đấy.

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\(\dfrac{7}{9}\cdot\dfrac{3}{35}=\dfrac{7}{3\cdot3}\cdot\dfrac{3}{7\cdot5}=\dfrac{1}{15}\)

\(\dfrac{9}{22}\cdot55=\dfrac{9}{11\cdot2}\cdot11\cdot5=\dfrac{45}{2}\)

\(\dfrac{11}{17}:\dfrac{33}{34}=\dfrac{11}{17}\cdot\dfrac{34}{33}=\dfrac{11\cdot17\cdot2}{17\cdot11\cdot3}=\dfrac{2}{3}\)

7/9 x 3/35 = 1/15

9/22 x 55 = 45/2

11/17 : 33/34 = 2/3

1/15     ;      45/2       ;      2/3