b: Ta có: \(1\frac{13}{15}\cdot\left(0,5\right)^2\cdot3+\left(\frac{8}{15}-1\frac{19}{60}\right):1\frac{23}{24}\)

\(=\frac{28}{15}\cdot3\cdot\frac14+\left(\frac{8}{15}-\frac{79}{60}\right):\frac{47}{24}\)

\(=\frac{28}{5}\cdot\frac14+\left(\frac{32}{60}-\frac{79}{60}\right)\cdot\frac{24}{47}=\frac75+\frac{-47}{60}\cdot\frac{24}{47}\)

\(=\frac75-\frac25=\frac55=1\)

c: \(\left(-2\right)^3\cdot\frac{-1}{24}+\left(\frac45-1,2\right):\frac{2}{15}\)

\(=\left(-8\right)\cdot\frac{-1}{24}+\left(\frac45-\frac65\right)\cdot\frac{15}{2}\)

\(=\frac13+\frac{-2}{5}\cdot\frac{15}{2}=\frac13-3=-\frac83\)

d: \(\left(-\frac25\right)^2+\frac12\cdot\left(4,5-2\right)-255\)

\(=\frac{4}{25}+\frac12\cdot2,5-255\)

=0,16+1,25-255

=-253,59

ngũ là j bn? hay là mũ

mũ nha mọi người em viết nhầm

`(-2)^3 . [-1] / 24 + ( 4 / 5 - 1,2 ) :  2/ 15`

`= -8 . [-1] / 24 + ( 4 / 5 - 6 / 5 ) . 15 / 2`

`= 1 / 3 + [-2] / 5 . 15 / 2`

`= 1 / 3 + (-3)`

`= [-8] / 3`

   (-2)³ . (-\(\dfrac{1}{24}\)) + ( \(\dfrac{4}{5}\) - 1,2): \(\dfrac{2}{15}\)

=   -8 .(-\(\dfrac{1}{24}\)) +  ( \(\dfrac{4}{5}\) - \(\dfrac{6}{5}\)) \(\times\) \(\dfrac{15}{2}\)

=              \(\dfrac{1}{3}\)  - \(\dfrac{2}{5}\)  \(\times\) \(\dfrac{15}{2}\)

=               \(\dfrac{1}{3}\) - 3

=                     -\(\dfrac{8}{3}\)

2) 13² - 5² = ( 13 - 5 )( 13 + 5 ) = 8 x 18 = 4 x 4 x 3 x 3 = 12²

`a)5/8x+2/5=1/5`

`=>5/8x=1/5-2/5`

`=>5/8x=-1/5`

`=>x=-1/5:5/8=-8/25`

`b)5/7:x+11/7=18/7`

`=>5/7:x=18/7-11/7`

`=>5/7:x=1`

`=>x=5/7`

`c)(-1,2).(-3/24)+(0,4-1 4/15):1 2/3`

`=(-6/5).(-1/8)+(2/5-19/15):5/3`

`=3/20+(-13/15)*3/5`

`=3/20-13/25=-37/100`

a)5/8.x+2/5=1/5

5/8.x=1/5 - 2/5

5/8.x=-1/5

x=(-1/5):5/8

x=(-1/5).8/5

x=-8/25.      Vậy x=-8/25

b)5/7:x +11/7=18/7

5/7:x=1

x=5/7:1

x=5/7.      Vậy x=5/7

ngũ hay mũ vậy bạn

xin lỗi nhé mũ

\(24\cdot5^5+5^2\cdot5^3\)

\(=24\cdot5^5+5^{2+3}\)

\(=24\cdot5^5+5^5\)

\(=5^5\cdot\left(24+1\right)\)

\(=5^5\cdot25\)

\(=5^5\cdot5^2\)

\(=5^7\)

`@` `\text {Ans}`

`\downarrow`

`24 * 5^5 + 5^2 * 5^3`

`= 24*5^5 +`\(5^{2+3}\)

`= 24*5^5 + 5^5`

`= 5^5* (24+1)`

`= 5^5*25`

`= 5^5*5^2`

`= 5^7`