\(a,2,3:0,25+7,7.4\\ =2,3.4+7,7.4\\ =\left(2,3+7,7\right).4=10.4=40\\ b,4,2.8+5,8:0,125\\ =4,2.8+5,8.8\\ =\left(4,2+5,8\right).8=10.8=80\\ c,3,4.4+5,6:0,25+4\\ =3,4.4+5,6.4+4\\ =\left(3,4+5,6+1\right).4=10.4=40\\ d,4:0,2+12:0,5+1,2:0,25\\ =4.5+12.2+1,2.4\\ 4.5+6.4+1,2.4\\ =4\left(5+6+1,2\right)\\ =4.12,2=48,8\)

❤

a: =5,67x(2,5x0,4)=5,67

b: =1,47(36+64)=1,47x100=147

c: =(0,25x40)x0,68=0,68

d: =25,8(1,02-1,01)=25,8x0,01=0,258

e: =0,7x(0,25x4)=0,7

g: =5,6(4+3+2+1)=5,6x10=56

h: =(2,5x4)x(12,5x0,8)=10x10=100

m: =7,89(54-53-1)=0

Xu cho bài ngắn thế:)

Bài 1:

12,6 x 2,4 = 30,24

364 – 54,684 = 309,316

102 + 68,57 = 170,57

96 x 34,6 = 3321,6

2,68 x 25% + 3,27 x 0,25 + 2,3 x \(\dfrac{1}{4}\) + 1,75:4

2,68 x 0,25 + 3,27 x 0,25 + 2,3 x 0,25 + 1,75 x 0,25

= 0,25 x (2,68 + 3,27 + 2,3 + 1,75)

= 0,25 x [ (2,68 + 3,27 + 1,75) + 2,3]

= 0,25 x [7,7 + 2,3]

= 0,25 x 10

= 2,5

2,8 x 92 + 5,6 : 0,25

= 2,8 x 92 + 2,8 x 2 x 4

= 2,8 x 92 + 2,8 x 8

= 2,8 x (92+8)

= 2,8 x 100

= 280

a) \(2,4:0,25+5,6:4+2\times\frac{1}{4}\)

\(=2,4\times\frac{1}{4}+5,6\times\frac{1}{4}+2\times\frac{1}{4}\)

\(=\left(2,4+5,6+2\right)\times\frac{1}{4}\)

\(=10\times\frac{1}{4}=\frac{5}{2}\)

b)\(3,47\times\frac{1}{2}-2,47:2+0,5\)

\(=3,47\times\frac{1}{2}-2,47\times\frac{1}{2}+\frac{1}{2}\times1\)

\(=\left(3,47-2,47+1\right)\times\frac{1}{2}\)

\(=2\times\frac{1}{2}=1\)

#Y/n

2,8 x 92 + 5,6 : 0,25

= 2,8 x 92 + 5,6 x 4

= 257,6     +     22,4

=          280

2,8 x 92 + 5,6 :0,25

= 2,8 x 92 +5,6 x 4

=257, 6 + 22 , 4

= 280

=3/4.0,25+3/4.1,25-3/4.0,5

=3/4.(0,25+1,25-0,5)

=3/4.10

=15/2

`3/4.0,25+3/4.1,25-3/4.0,5`

`=3/4.(0,25+1,25-0,5)`

`=3/4xx10=15/2`

\(7,5:0,25+13,3\times4+3,5:\dfrac{1}{4}\)
\(=7,5\times4+13,3\times4+3,5\times4\)
\(=\left(7,5+13,3+3,5\right)\times4\)
\(=24,3\times4=97,2\)