\(6\sqrt{6}-27=\left(\sqrt{6}-3\right)\left(9+3\sqrt{6}\right)\)

\(=\left(5xy+8xy-95xy+8xy\right)+\left(-3y-6y-3y-6y\right)+6+6-9\)

\(=-74xy-18y+3\)

6x4=24

= 6 x 4

= 24

mik mới bị trừ 280 xong, các bn giúp mik nha

Cảm ơn trc

6+6+6+6=6x4

\(\sqrt{15-6\sqrt{6}}=\sqrt{15-2\sqrt{54}}=\sqrt{9-2\sqrt{9}\sqrt{6}+6}=\sqrt{\left(3-\sqrt{6}\right)^2}=\left|3-\sqrt{6}\right|=3-\sqrt{6}\)

\(\dfrac{6}{84}+\dfrac{6}{210}+\dfrac{6}{390}+...+\dfrac{6}{2100}\)

\(=\dfrac{2}{28}+\dfrac{2}{70}+\dfrac{2}{130}+...+\dfrac{2}{700}\)

\(=\dfrac{2}{4.7}+\dfrac{2}{7.10}+\dfrac{2}{10.13}+...+\dfrac{2}{25.28}\)

\(=\dfrac{2}{3}.\left(\dfrac{3}{4.7}+\dfrac{3}{7.10}+\dfrac{3}{10.13}+...+\dfrac{3}{25.28}\right)\)

\(=\dfrac{2}{3}.\left(\dfrac{1}{4}-\dfrac{1}{7}+\dfrac{1}{7}-\dfrac{1}{10}+...+\dfrac{1}{25}-\dfrac{1}{28}\right)\)

\(=\dfrac{2}{3}\left(\dfrac{1}{4}-\dfrac{1}{28}\right)\)

\(=\dfrac{1}{7}\)

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Giải hộ mình đi các bạn ơi

B = 1/1.2+1/2.3+1/3.4+1/4.5+1/5.6+1/6.7

B = 1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7

B = 1 - 1/7

B = 6/7 

\(B=\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+\frac{1}{5.6}+\frac{1}{6.7}\)

\(=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}\)

\(=1-\frac{1}{7}\)

\(=\frac{6}{7}\)

\(\sqrt{15-6\sqrt{6}}+\sqrt{33-12\sqrt{6}}\)

\(=\sqrt{\left(3-\sqrt{6}\right)^2}+\sqrt{\left(2\sqrt{6}-3\right)^2}\)

\(=3-\sqrt{6}+2\sqrt{6}-3=\sqrt{6}\)

C = 6/2.5 + 6/5.8 + 6/8.11 +...+ 6/29.32
C = 2.(3/2.5 + 3/5.8 + 3/8.11 + ... + 3/29.32)
C = 2.(1/2 - 1/5 + 1/5 - 1/8 + 1/8 - 1/11 + ... + 1/29 - 1/32)
C = 2.(1/2 - 1/32)
C = 2.15/32
C = 15/16

Con cặc