\(\left(-36\right)+45+\left[32.\left(-2\right)-\left(-155\right)\right]\\ =\left(-36\right)+45+\left[-64-\left(-155\right)\right]\\ =\left(-36\right)+45+\left[-64+155\right]\\ =\left(-36\right)+45+91\\ =9+91\\ =100\)

(-36) + 45 + [32 . (-2) - (-155)]

= (-36) + 45 +[(-64) + 155]

= (-36) + 45 - 64 + 155

=(-36 - 64) + (45 + 155)

= -100 + 200

= 100

\(\left(-36\right)+45+\left[32\times\left(-2\right)-\left(-155\right)\right]\)

\(=\left(-36\right)+45+\left(-64\right)+155\)

\(=\left[\left(-36\right)+\left(-64\right)\right]+\left(45+155\right)\)

\(=-100+200\)

\(=100\)

Chụp thẳng lại đc ko pẹn !

bạn làm rồi còn gì

chắc là D hay sao ý

D

d

ABC vuông cân \(\Rightarrow\left\{{}\begin{matrix}AC=AB=3\\BC=AB\sqrt{2}=3\sqrt{2}\end{matrix}\right.\)

\(\overrightarrow{BC}.\overrightarrow{CA}=-\overrightarrow{CB}.\overrightarrow{CA}=-BC.AC.cos\left(\overrightarrow{CB};\overrightarrow{CA}\right)\)

\(=-3\sqrt{2}.3.cos45^0=-9\)

3x + 4x + 8x - 2( 32 + 8 ) = 30

15x - 2.40 = 30

15x - 80 = 30

15x = 30 + 80

15x = 110

x = 110 : 15

x = 22/3

3x+4x+8x - 2.(32+8) = 30

( 3 + 4 + 8 )x - 2.40 = 30

15x - 80= 30

15x  = 30 + 80 = 110 

x = 110 : 15 = \(\frac{22}{3}\)

\(\dfrac{21}{32}:\dfrac{1}{16}.\dfrac{4}{9}\)

\(=\dfrac{21.16.4}{32.9}\)

\(=\dfrac{3.7.32.2}{32.3.3}\)

\(=\dfrac{14}{3}\)

a) \(\dfrac{49}{81}=\dfrac{7^x}{9^x}\)(sửa đề)

\(\Leftrightarrow\left(\dfrac{7}{9}\right)^2=\left(\dfrac{7}{9}\right)^x\)\(\Rightarrow x=2\)

b) \(\dfrac{-64}{343}=\left(-\dfrac{4^x}{7^x}\right)\)(sửa đề)

\(\Leftrightarrow\left(-\dfrac{4}{7}\right)^3=\left(-\dfrac{4}{7}\right)^x\) \(\Rightarrow x=3\)

c) \(\dfrac{9}{144}=\dfrac{3^x}{12^x}\)(sửa đề)

\(\Leftrightarrow\left(\dfrac{3}{12}\right)^2=\left(\dfrac{3}{12}\right)^x\Rightarrow x=2\)

d) \(-\dfrac{1}{32}=\left(-\dfrac{1^x}{2^x}\right)\)(sửa đề)

\(\Leftrightarrow\left(-\dfrac{1}{2}\right)^5=\left(-\dfrac{1}{2}\right)^x\Rightarrow x=5\)

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