222 x 5 = 111 x 2 x 5 = 1110
3 x 125 x 2 x 8 = (3 x2 ) x (125 x 8) = 6000
342 x 5 = 340 + 2 x 5 = 340 x 10 = 3400
25 x 8 x 9 = (25 x 4) x (4 x 9) = 100 x 36 = 3600
Đúng hay sai

Đúng

Đúng

Sai

Sai

222 x 5 = 111 x 2 x 5 = 1110
=> Đúng 

3 x 125 x 2 x 8 = (3 x2 ) x (125 x 8) = 6000
=> Đúng 

342 x 5 = 340 + 2 x 5 = 340 x 10 = 3400
=> Sai 

ay sai?25 x 8 x 9 = (25 x 4) x (4 x 9) = 100 x 36 = 3600

=> Sai 

b: =100x1000=100000

a)=\(\left[72.\left(-2\right)\right].\left[-50.\left(-2\right)\right]\)

=-144.100

=-14400

b)=(125.8).(-5).(-20)

=1000.100

=100000

c)=\(\left[125.\left(-4\right)\right]\).(-3).(-32)

=-500.96

=-48000

d)=-492.125

=-60500

A=-1042

B=-38100

C=9316

D=-50

Bạn làm rõ ra được ko

\(a,=\dfrac{1}{3}\times\left(\dfrac{1}{2}+\dfrac{1}{3}\right)=\dfrac{1}{3}\times\dfrac{5}{6}=\dfrac{5}{18}\\ b,=\dfrac{4}{5}\times\left(\dfrac{1}{2}-\dfrac{1}{3}\right)=\dfrac{4}{5}\times\dfrac{1}{6}=\dfrac{2}{15}\\ c,=456\times99-6\times99+456\\ =456\times\left(99+1\right)-594\\ =456\times100-594=45600-594=45006\\ d,=101\times\left(101-1\right)=101\times100=10100\)

`a, 350, 222, 456, 800`

`b, 125, 350, 555, 800`

`c, 350, 800`

`d, 222, 456`

`e, 125, 555`

`f, 222, 555, 456`

`g, 350, 125, 800

Sunshine ơi, bạn thiếu câu i và câu j

a, 350; 222; 456; 800

b, 125; 350; 555; 800

c, 350; 800

d, 222; 456

e, 125; 555

f, 222; 555; 456

g, 350; 125; 800

h, 222; 456

\(A=\left(6-\dfrac{2}{3}+\dfrac{1}{2}\right)-\left(5+\dfrac{5}{3}-\dfrac{3}{2}\right)-\left(3-\dfrac{7}{3}+\dfrac{5}{2}\right)\\ A=\dfrac{35}{6}-\dfrac{31}{6}-\dfrac{19}{6}=-\dfrac{15}{6}\)

a: \(=\left\{145-\left[130-10\right]:2\right\}\cdot5\)

\(=\left\{145-60\right\}\cdot5=85\cdot5=425\)

b: \(=100:\left\{250:\left[450-4\cdot125+4\cdot25\right]\right\}\)

\(=\dfrac{100}{250:\left[450-500+100\right]}=\dfrac{100}{250:50}=\dfrac{100}{5}=20\)

c: \(=355-5\cdot\left[64-\left(27-25\right)\right]=355-5\cdot\left[64-2\right]\)

\(=355-310=45\)

a) 21.(-35)-3.(-25).7=21.(-35)-(21.(-25)=21(-35+25)=21.(-10)=-210

b)77-11(30+7)=77-11.7+11.30=77-77-330=-330

c)85(35-27)-35(85-27)=85.35-85.27-35.85+35.27=(85.35-35.85)+(35.27-85.27)=35.27-85.27=27(35-85)=27.(-50)=-1350

d)(-25).68+(-34).(-250)=-25.68+34.2.125=-25.68+68.125=68(125-25)=68.100=6800

e)125.(-61).(-2^3).(-1)^2n+1=125.(-61).(-8).(-1)=(-8.125).61=-1000.61=-61000

h) đặt S=2¹⁰⁰-2⁹⁹-2⁹⁸-...-2²-2-1=2^100-(2^99+2^98+2^97+...+2+1)=2^100-A

ta có: A=2^99+2^98+2^97+...+2+1

2A=2^100+2^99+2^98+...+2^2+2

=>2A-A=(2^100+2^99+2^98+...+2^2+2)-(2^99+2^98+2^98+...+2+1)

=>A=2^100-1

=>S=2^100-(2^100-1)=2^100-2^100+1=1

A=2^100

a là bằng -210

ý b bằng -330

ý c bằng -1350

ý d bằng 6800

ý f bằng 225

tớ làm được 5 ý , tich nha bạn

a, 21.(-35)-3.(-25).7

=21.(-35)-(3.7).(-25)

=21.(-35)-21.(-25)

=21.[(-35)-(-25)]

=21.(-10)

=-210