\(A=12\dfrac{2}{5}.\left(\dfrac{-7}{3}\right)-3\dfrac{2}{5}.\left(\dfrac{-7}{3}\right)\)

\(A=\dfrac{62}{5}.\left(\dfrac{-7}{3}\right)-\dfrac{17}{5}.\left(\dfrac{-7}{3}\right)\)

\(A=\left(\dfrac{-7}{3}\right).\left(\dfrac{62}{5}-\dfrac{17}{5}\right)\)

\(A=\left(\dfrac{-7}{3}\right).\dfrac{45}{5}\)

\(A=-21\)

\(B=\left(\dfrac{2}{3}\right)^3:\left(\dfrac{2}{3}\right)^2+\left(-1\dfrac{1}{2}\right):150\%\)

\(B=\left(\dfrac{2}{3}\right)^1-\dfrac{3}{2}:1,5\)

\(B=\dfrac{2}{3}-\dfrac{3}{2}:\dfrac{3}{2}\)

\(B=\dfrac{2}{3}-1\)

\(B=-\dfrac{1}{3}\)

A = \(12\dfrac{2}{5}\) . (\(\dfrac{-7}{3}\)) - \(3\dfrac{2}{5}\) . (\(\dfrac{-7}{3}\))

A = (\(\dfrac{-7}{3}\)) . ( \(12\dfrac{2}{5}\) - \(3\dfrac{2}{5}\) )

A = (\(\dfrac{-7}{3}\)) . ( \(\dfrac{62}{5}\) - \(\dfrac{17}{5}\) )

A = (\(\dfrac{-7}{3}\)) . 9

A = \(\dfrac{-7.9}{3}\)

A = \(\dfrac{-63}{3}\) = -21

B = \(\left(\dfrac{2}{3}\right)^3\) : \(\left(\dfrac{2}{3}\right)^2\) + \(\left(-1\dfrac{1}{2}\right)\) : 150 %

B = \(\left(\dfrac{2}{3}\right)^{3-2}\) + \(\dfrac{-3}{2}\) : \(\dfrac{3}{2}\)

B = \(\dfrac{2}{3}\) + -1

B = \(\dfrac{-1}{3}\)

a: =3/4-5/4+3/2x12/5=-1/2+36/10=-5/10+36/10=31/10

b: \(=\dfrac{-7}{13}\left(\dfrac{5}{9}+\dfrac{4}{9}\right)+\dfrac{7}{13}+8=8\)

\(z^2\) hay \(2z^2\)

2^2

a) \(3\sqrt{3}=\sqrt{27}>\sqrt{12}\)

b) \(3\sqrt{5}=\sqrt{45}>\sqrt{27}\)

c) \(\dfrac{1}{3}\sqrt{51}=\sqrt{\dfrac{51}{9}}< \sqrt{\dfrac{54}{9}}=6=\sqrt{\dfrac{150}{25}}=\dfrac{1}{5}\sqrt{150}\)

d) \(\dfrac{1}{2}\sqrt{6}=\sqrt{\dfrac{6}{4}}=\sqrt{\dfrac{3}{2}}< \sqrt{\dfrac{36}{2}}=6\sqrt{\dfrac{1}{2}}\)

a)S

b)S

c)Đ

d)Đ

S

S

Đ

Đ

A + \(\dfrac{3}{2}\) B = 150⁰ ⇒ 2A + 3B   = 300⁰ 

                             2A  + \(\dfrac{1}{2}\) B = 150⁰

Trừ vế cho vế ta được : 3B - \(\dfrac{1}{2}\)B = 150⁰  

                                    ⇒ B = 150⁰: (3 -\(\dfrac{1}{2}\))

                                    ⇒ B = 60⁰

                                     ⇒ A = 150⁰ - 60⁰ x \(\dfrac{3}{2}\) 

                                     ⇒A = 60⁰

Vậy tam giác ABC là tam giác đều 

a) \(\dfrac{3}{7}\) của 14 hình thoi là \(6\) hinh thoi 

\(\dfrac{5}{6}\) của 18 bông hoa là \(15\) bông hoa 

b) \(\dfrac{1}{3}\) của 18 là: \(6\)

\(\dfrac{2}{7}\) của 42 là: \(12\)

\(\dfrac{3}{5}\) của 80 là: \(48\) 

\(\dfrac{1}{8}\) của 64 là: \(8\)

\(\dfrac{4}{9}\) của 27 là: \(12\) 

\(\dfrac{5}{8}\) của 96 là: \(60\)

đề bài là gì ạ

so sánh hay gì ạ

....

a) Ta có:

\(2\sqrt{3}=\sqrt{2^2.3}=\sqrt{12}.\)

Mà \(\sqrt{12}< \sqrt{13}\)

Nên \(2\sqrt{3}< \sqrt{13}\) 

b) Ta có:

\(7=\sqrt{49}\)

\(3\sqrt{5}=\sqrt{3^2.5}=\sqrt{45}\)

Mà \(\sqrt{45}< \sqrt{49}\)

Nên \(7>3\sqrt{5}\)

a: Sai

b: Đúng

c: Sai