\(4^x:2^6=2^8\)

\(\Rightarrow\left(2^2\right)^x:2^6=2^8\)

\(\Rightarrow2^{2x}:2^6=2^8\)

\(\Rightarrow2^{2x-6}=2^8\)

\(\Rightarrow2x-6=8\)

\(\Rightarrow2x=14\)

\(\Rightarrow x=\dfrac{14}{2}\)

\(\Rightarrow x=7\)

4x:26=28

⇒(22)�:26=28⇒(22)x:26=28

⇒22�:26=28⇒22x:26=28

⇒22�−6=28⇒22x−6=28

⇒2�−6=8⇒2x−6=8

⇒2�=14⇒2x=14

⇒�=142⇒x=214​

⇒�=7⇒x=7

Bạn nên viết lại đề bài bằng công thức toán để được hỗ trợ tốt hơn.

a) A = 2004 . 2004 = 2004² > 2002² = 2002 x 2002 = B

Vậy A > B

b) C = 143 . 143 = 143²

D = 140 . 146 + 140

D = (143 - 3)(143 + 3) + 140

D = 143² - 9 + 140 = 143² + 131 > 143² = C

Vậy C < D 

c) E = 27 . 58 = 26 . 58 + 58 > 27 + 58 . 26 = F

Vậy E > F 

\(\dfrac{1}{15}+\dfrac{1}{35}+\dfrac{1}{99}+\dfrac{1}{143}+\dfrac{1}{195}\\ =\dfrac{1}{15}+\dfrac{1}{35}+\dfrac{1}{63}+\dfrac{1}{99}+\dfrac{1}{143}+\dfrac{1}{195}-\dfrac{1}{63}\\ =\dfrac{1}{2}\left(\dfrac{2}{3.5}+\dfrac{2}{5.7}+\dfrac{2}{7.9}+\dfrac{2}{9.11}+\dfrac{2}{11.13}+\dfrac{2}{13.15}\right)-\dfrac{1}{63}\\ =\dfrac{1}{2}\left(\dfrac{1}{3}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{7}+\dfrac{1}{7}-\dfrac{1}{9}+\dfrac{1}{9}-\dfrac{1}{11}+\dfrac{1}{11}-\dfrac{1}{13}+\dfrac{1}{13}-\dfrac{1}{15}\right)-\dfrac{1}{63}\\ =\dfrac{1}{2}\left(\dfrac{1}{3}-\dfrac{1}{15}\right)-\dfrac{1}{63}=\dfrac{1}{2}.\dfrac{4}{15}-\dfrac{1}{63}=\dfrac{2}{15}-\dfrac{1}{63}=\dfrac{37}{315}\)

\(0,25\cdot1\dfrac{3}{5}\cdot\left(\dfrac{5}{4}\right)^2:-\dfrac{4}{7}\)

\(=\dfrac{1}{4}\cdot\dfrac{8}{5}\cdot\dfrac{25}{16}\cdot-\dfrac{7}{4}\)

\(=\dfrac{8\cdot25\cdot-7}{4\cdot5\cdot16\cdot4}\)

\(=\dfrac{1\cdot5\cdot-7}{4\cdot1\cdot2\cdot4}\)

\(=-\dfrac{35}{32}\)

nhanh

nhanh

\(\left(4-\dfrac{5}{12}\right):\left(2+\dfrac{5}{24}\right)\)

\(=\dfrac{43}{12}:\dfrac{53}{24}\)

\(=\dfrac{43}{12}\cdot\dfrac{24}{53}\)

\(=\dfrac{43\cdot2}{1\cdot53}\)

\(=\dfrac{86}{53}\)

D = 500 - {5.[409 - (2³ . 3 + 21)²] - 1724}

D = 500 - {5.[409 - (8 . 3 + 21)²] - 1724}

D = 500 - {5.[409 - (24 + 21)²] - 1724}

D = 500 - {5.[409 - 45²] - 1724}

D = 500 - {5.[409 - 2025] - 1724}

D = 500 - {5.(-1616) - 1724}

D = 500 - {-8080 - 1724}

D = 500 - (-9804)

D = 500 + 9804

D = 10304

D=500-\(\left\{5\cdot[409-\left(2^3\cdot3+21\right)^2-1724\right\}\)=500-\(\left\{5\cdot[409-45^2-1724]\right\}\)

=500-\(\left\{5\cdot[409-2025-1724]\right\}\)=500-\(\left\{5\cdot\left(-3340\right)\right\}\)=500+16700=17200.

   (4 - \(\dfrac{5}{12}\)) : 2 + \(\dfrac{5}{24}\)

= (\(\dfrac{48}{12}\) - \(\dfrac{5}{12}\)) x \(\dfrac{1}{2}\) + \(\dfrac{5}{24}\)

= \(\dfrac{43}{12}\) x \(\dfrac{1}{2}\) + \(\dfrac{5}{24}\)

= \(\dfrac{43}{24}\) + \(\dfrac{5}{24}\)

= \(\dfrac{48}{24}\)

= 2

2

\(2^3-5^7:5^6+8\cdot3^3\)

\(=8-5^{7-6}+8\cdot27\)

\(=8-5+216\)

\(=219\)

2³ - 5⁷ : 5⁶ + 8 . 3³

= 8 - 5 + 8 . 27

= 3 + 216

= 219

Vì 28 : 5 = 5 (dư 3 bạn)

Vậy cần gọi thêm ít nhất số bạn để chia đủ cho các đội là :

      5 - 3 = 2 (bạn)

        Đáp số : 2 bạn

2 bạn nhaa!