=169344

CHO HỎI ĐỀ BÀI

\(\frac{15x24x7}{5x16x21}=\frac{3x3x1}{1x2x3}=\frac{9}{6}=\frac{3}{2}\)

x7 = 21

=> x = 21 : 7 = 3

đúng là 7

=77(5x7+65)-21x57-21x43

=77x100-(21x57+21x43)

=7700-21(57+43)

=7700-21.100

=7700-2100

=5600

= 1 - 1 3 + 1 3 - 1 5 + 1 5 - 1 7 + 1 7 - 1 11 + 1 11 = 1   - 1 11 = 10 11

\(\frac{8.15.42}{16.21.45}=\frac{8.15.21.2}{8.2.21.15.3}=\frac{1}{3}\)

\(\frac{25.33.60.7}{21.65.121.48}=\frac{5.5.11.2.12.5.7}{7.3.13.5.11.12.12.4}=\frac{25}{572}\)

Đề : Em muốn tham gia học ngoại khóa môn bơi lội  ở nhà văn hóa thiếu nhi tiinhr đồng nai. Em hãy viết lá đơn xin tham gia khóa học đó

làm hộ mình nhé 

\(\frac{8\cdot15\cdot42}{16\cdot21\cdot45}=\frac{8\cdot15\cdot21\cdot2}{2\cdot8\cdot21\cdot15\cdot3}=\frac{1}{3}\)

\(\frac{25\cdot33\cdot60\cdot7}{21\cdot65\cdot121\cdot48}=\frac{5\cdot5\cdot3\cdot11\cdot12\cdot5\cdot7}{3\cdot7\cdot13\cdot5\cdot11\cdot11\cdot12\cdot4}=\frac{5\cdot5}{13\cdot11\cdot4}=\frac{25}{572}\)

\(\Leftrightarrow y\times\left(\dfrac{1}{7}+\dfrac{9}{21}+\dfrac{7}{3}\right)=\dfrac{5}{3}\)

\(\Leftrightarrow y\times\dfrac{61}{21}=\dfrac{5}{3}\)

\(\Leftrightarrow y=\dfrac{5}{3}:\dfrac{61}{21}=\dfrac{35}{61}\)

y x (1/7 +9/21 +7/3)= 5/3

y x 61/21 = 5/3

y = 5/3 : 61/21

y= 35/61

\(G=1,75.\left(-\frac{16}{21}\right)-\left(\frac{13}{3}+2,25\right):\frac{158}{60}\)

\(G=-4,3-\frac{79}{12}:\frac{79}{30}\)

\(G=-\frac{4}{3}-\frac{5}{2}\)

\(G=-\frac{23}{6}\)

=1,75.(−1621)−(133+2,25):15860

=−4,3−7912:7930

=−43−52

à mk nhầm, cái này mới đúng:

=$1,75.\left(-\frac{16}{21}\right)-\left(\frac{13}{3}+2,25\right):\frac{158}{60}$

$=-4,3-\frac{79}{12}:\frac{79}{30}$

$=-\frac{4}{3}-\frac{5}{2}$

$=-\frac{23}{6}$