c: \(=520:\left\{\left[\left(80+20\right):2-2\right]+82\right\}+1\)

\(=520:\left\{48+82\right\}+1\)

=4+1

=5

a: \(=100\cdot104=10400\)

d: \(=2\cdot9+4\cdot27=18+108=126\)

\(=13\left(55+85\right)+87\left(51+69\right)\)

\(=13\cdot140+87\cdot120\)

\(=12260\)

\(a.3\times2^3+3\times4^2\)

  \(=3\times2^3+3\times\left(2^2\right)^2\)

   \(=3\times2^3+3\times2^4\)

   \(=3\times\left(2^3+2^4\right)=3\times\left(8+16\right)=3\times24=72\)

đợi mình nhé

a)3 . 2³ + 3 . 4²

=3. ( 2³ + 4² )

=3. ( 8 + 16 )

=3. 24

=72

Phần b) đang giải nhé

cần gấp nha mn

\(520:\left\{\left[\left(16\cdot5+2^2\cdot5\right):5-5\right]+115\right\}+2017^0\)

\(520:\left\{\left[\left(80-20\right):5-5\right]+115\right\}+1\)

\(520:\left\{\left[60:5-5\right]+115\right\}+1\)

\(520:\left(7+115\right)+1\)

\(520:122+1\)

\(=5,2\)

520 : { [ (16 x 5 + 2² x 5 ) ) : 5 - 5  ] + 115 } + 2017 ⁰

= 520 : { [ (80 + 20) : 5 - 5 ] + 115 } + 1

= 520 : { [ 100 : 5 - 5 ] + 115 } +1

= 520 : { [ 20 - 5 ] + 115 } +1

= 520 : { 15 + 115 } +1

= 520 : 130 +1

= 4 + 1

= 5

\(B=1+3+3^2+3^3+...+3^{2017}\)

\(B=1+3\left(1+3+3^2+...+3^{2016}\right)\)

\(B=1+3\left(B-3^{2017}\right)\)

\(B=1+3B-3^{2018}\)

\(2B=3^{2018}-1\Rightarrow B=\frac{3^{2018}-1}{2}\)