\(a,=-17+91-91+17+2011=\left(-17+17\right)+\left(91-91\right)+2011\)

\(=0+0+2011=2011\)

b)\(=\dfrac{4}{7}+\dfrac{1}{6}-0,375.4=\dfrac{31}{42}-\dfrac{3}{2}=-\dfrac{16}{21}\)

\(b)\) \(\dfrac{4}{7}\) + \(\dfrac{5}{6}\) : \(5\) \(- 0,375 .(-2)\)²\(=\) \(\dfrac{4}{7}\) + \(\dfrac{1}{6}\) - \(0,375\) . \(4\)

= \(\dfrac{4}{7}\) + \(\dfrac{1}{6}\) - \(\dfrac{3}{2}\) = \(\dfrac{4.6}{42}\) +  \(\dfrac{1.7}{42}\) - \(\dfrac{3.21}{42}\) = \(-\)\(\dfrac{16}{21}\)

\(\frac{-1}{3}:\frac{-5}{6}=\frac{-1}{3}\times\frac{-6}{5}=\frac{2}{5}\)

@muối

(-1/3) : (-5/6) = 2/5

\(\frac{-1}{3}:\frac{-5}{6}\)

\(=\frac{-1}{3}.\frac{6}{-5}\)

\(=\frac{-6}{-15}\)

\(=\frac{-2}{-5}\)

\(=\frac{2}{5}\)

4³.2⁵.16=(2²)³.2⁵.2⁴=2⁶.2⁵.2⁴=2¹⁵

32.64.8²=2⁵.2⁶.2⁶=2¹⁷

=> A=2¹⁷:2¹⁵=2^17-15=2²=4

Đáp số: A=4

\(\frac{32.64.8^2}{4^3\cdot2^5\cdot16}=\frac{2^5.2^6.2^6}{2^6.2^5.2^3}\)

\(=\frac{2^{5+6+6}}{2^{6+5+3}}=\frac{2^{17}}{2^{14}}=2^{17-14}=2^3=8\)

Mình giải thích thêm nha 

\(8^2=\left(2^3\right)^2=2^6\)

\(4^3=\left(2^2\right)^3=2^6\)

12 : 0,5 - 12 * 0,75 - 12 * 0,25

= 12 * 2 - 12 * 0,75 - 12 * 0,25

= 12 * ( 2 - 0,75 - 0,25 )

= 12 * 1

=12

12:0,5-12x0,75-12x0,25

=12x2-12x0,75-12x0,25

=12x(2-0,75-0,25)

=12x1

=12

           Cho mình một tích đúng nhé

$67\cdot12+67\cdot89-67$

$=67\cdot(12+89-1)$

$=67\cdot(101-1)$

$=67\cdot100$

$=6700$

\(\dfrac{5}{7}\).\(\dfrac{-3}{11}\)-\(\dfrac{5}{7}\).\(\dfrac{8}{11}\)+1\(\dfrac{5}{7}\)

= \(\dfrac{5}{7}\).(\(\dfrac{-3}{11}\) - \(\dfrac{8}{11}\)) + 1\(\dfrac{5}{7}\)

= \(\dfrac{5}{7}\). -1             + 1\(\dfrac{5}{7}\)

= \(\dfrac{-5}{7}\)               +1\(\dfrac{5}{7}\)

= -1

\(\dfrac{5}{7}.-\dfrac{3}{11}-\dfrac{5}{7}.\dfrac{8}{11}+1\dfrac{5}{7}\)

\(=\dfrac{5}{7}.\left(\dfrac{3}{11}-\dfrac{8}{11}\right)+1\dfrac{5}{7}\)

\(=\dfrac{5}{7}.\left(-1\right)+1\dfrac{5}{7}\)

\(=1\)

Đúng rồi đó tick nha bạn