\(=\dfrac{\left(20\cdot16-12\cdot8-48\cdot4\right)^2}{-2^9}=\dfrac{2^{10}}{-2^9}=-2\)

A = 1 + 3²+3⁴+...+3¹⁰⁰

9A= 3²+3⁴+3⁶+...+3¹⁰²

=>9A-A=(3²+3⁴+3⁶+...+3¹⁰²)-(1 + 3²+3⁴+...+3¹⁰⁰)

<=>8A=3¹⁰²-1

=>A=\(\frac{3^{102}-1}{8}\)

Tương tự với câu B, nhân B cho 7²=49

B=7+7³+7⁵+...+7⁹⁹

49B=7³+7⁵+7⁷+...+7¹⁰¹

49B-B=7¹⁰¹-7

=>B=\(\frac{7^{101}-7}{48}\)

Đề bài có phải là như vậy ko bạn:

5^x-2 - 3²= 2⁴- (6⁸ : 6⁶ - 6²) ( x^2-1)⁴ =81

( 3^x+4 )² = 19⁶ : ( 19³ x 19² ) - 3^{1x 2005}

Bạn xem hộ mik như vậy có đúng đề ko, đúng thì mik làm cho nhé!

\(c=2^3.5^3-\left\{7^2.2^3-5^2.\left[4^3::8+11^2:121-2\left(37-5.7\right)\right]\right\}\)

\(c=8.5-\left\{49.8-25.\left[8:8+121:121-2\left(37-5.7\right)\right]\right\}\)

\(c=8.5-\left\{49.8-25.\left[8:8+121:121-2\left(37-35\right)\right]\right\}\)

\(c=8.5-\left\{49.8-25.\left[8:8+121:121+2.2\right]\right\}\)

\(c=8.5-\left\{1+1+2.2\right\}\)

\(c=8.5-\left\{1+1+4\right\}\)

\(c=8.5-6\)

\(c=40-6\)

\(c=34\)

nhầm

\(c=2^3.5^3-\left\{7^2.2^3-5^2.\left[4^3:8+11^2:121-2\left(37-5.7\right)\right]\right\}\)

\(c=8.125-\left\{49.8-25.\left[8:8+121:121-2\left(37-35\right)\right]\right\}\)

\(c=8.125-\left\{49.8-25.\left[8:8+121:121-2.2\right]\right\}\)

\(c=8.125-\left\{49.8-25.\left[1+1-2.2\right]\right\}\)

\(c=8.125-\left\{49.8-25.\left[1+1-4\right]\right\}\)

\(c=8.125-\left\{49.8-25.-2\right\}\)

\(c=8.125-\left\{392+50\right\}\)

\(c=8.125-442\)

\(c=1000-442\)

\(c=558\)

\(2\cdot8^{15}\cdot4\cdot8^{20}=\left(2\cdot4\right)\cdot8^{15+20}=8\cdot8^{35}=8^{36}\)