Giúp em với ạ

a,  5 3 + 3 4 + 4 . 2 + 27 - 3 : 4

= 125+170+6

= 301

b,  124 : 3 2 . 7 - 1 10 + 24 : 5 2

= 124:[9.7–(1+24):25]

= 124 : [63–25:25]

= 124:62

= 2

c,  245 - 4 16 : 8 + 2 4 . 3 2 - 9

= 245–4[2+2.27]

= 245–4.45

= 29

d,  375 : 5 3 - 3 8 : 3 6 - 2 . 2 3

= 375 : 125 – (9–16)

= 3–9+16

= 10

hình như là 3² chứ k f 3³

\(B=\frac{1^2}{1\cdot2}\cdot\frac{2^2}{2\cdot3}\cdot\frac{3^2}{3\cdot4}\cdot\frac{4^2}{4\cdot5}\)

\(B=\frac{\left(1\cdot1\right)\left(2\cdot2\right)\left(3\cdot3\right)\left(4\cdot4\right)}{\left(1\cdot2\right)\left(2\cdot3\right)\left(3\cdot4\right)\left(4\cdot5\right)}\)

\(B=\frac{\left(1\cdot2\cdot3\cdot4\right)\left(1\cdot2\cdot3\cdot4\right)}{\left(1\cdot2\cdot3\cdot4\right)\left(2\cdot3\cdot4\cdot5\right)}\)

\(=\frac{1}{5}\)

\(B=\frac{1^2}{1\cdot2}\cdot\frac{2^2}{2\cdot3}\cdot\frac{3^2}{3\cdot4}\cdot\frac{4^2}{4\cdot5}\)

\(B=\frac{1^2\cdot2^2\cdot3^2\cdot4^2}{1\cdot2\cdot2\cdot3\cdot3\cdot4\cdot4\cdot5}\)

\(B=\frac{1^2\cdot2^2\cdot3^2\cdot4^2}{1^2\cdot2^2\cdot3^2\cdot4^2\cdot5}=\frac{1}{5}\)