125 + (13 + 7) = 125 + 20 = 145

416 – (25 - 11) = 416 - 14 = 25

\(25-\left(20-10\right)=25-10=15\)

\(80-\left(30+25\right)=80-30-25=50-25=25\)

\(125+\left(13+7\right)=125+20=145\)

\(416-\left(25-11\right)=416-14=402\)

\(25-\left(20-10\right)\)

= \(25-10\)

= \(15\)

\(80-\left(30+25\right)\)

= \(80-55\)

= \(25\)

\(125+\left(13+7\right)\)

= \(125+20\)

= \(145\)

\(416-\left(25-11\right)\)

= \(416-14\)

= \(402\)

giúp mình với mình bảo cả nhà mình vào tick cho bạn

2 giờ 25 phút x 3 – 3,8 giờ *

=  7 giờ 15 phút - 3,8 giờ

=3,45 giờ

13,6 giờ : 8 + 2 giờ 7 phút *

= 1,7 giờ + 2 giờ 7 phút

= 3.7 giờ 7 phút 

\(=25\%+25\%\times38+25\%\times50+25\%\times11\)

\(=25\%\times\left(1+38+50+11\right)=25\%\times100=25\)

\(\dfrac{25}{100}+\dfrac{1}{4}\times38+25\%\times50+0,25\times11\)

\(0,25+0,25\times38+0,25\times50+0,25\times11+1\)

\(0,25\times\left(38+50+11+1\right)\)

\(0,25\times100\)

\(25\)

\(a,\left(23+x\right)-\left(56-x\right)=\left(23+7\right)-\left(56-7\right)=30-49=-19\\ b,25-x-\left(29+y-8\right)=25-13-\left(29+11-8\right)=12-32=-20\)

a) (23 + x)- (56 -x)

=23 + x - 56 + x ( áp dụng quy tắc bỏ ngoặc)

=(23-56)+ (x+x)= 2x-33

=2.7-33= 14-33= -19

b) 25 -x - (29 + y - 8)

=25 - x - 29 - y + 8

=4 - x - y= 4 - 13 - 11= -20

=

a) 5

b) 11/6

a) Cách 1: Thay x = 7, ta có:

(23 + x) - (56 - x)

= (23 + 7) - (56 - 7)

= 30 - 49

= -19

Cách 2: 

Thay x = 7, ta có:

(23 + x) - (56 - x)

= (23 + 7) - (56 - 7)

= 23 + 7 - 56 + 7

= 30 - 56 + 7

= (-26) + 7

=-19.

b)  Cách 1: Thay x = 13, y = 11, ta có:

25 - x - (29 + y - 8)

= 25 - 13 - (29 + 11 - 8)

= 12 - 32

= -20.

Cách 2: Thay x = 13, y = 11, ta có:

25 - x - (29 + y - 8)

= 25 - 13 - (29 + 11 - 8)

= 25 - 13 - 29 - 11 + 8

= 12 - 29 - 11 + 8

= (-17) - 11 + 8

= (-28) + 8

=-20.

a) (2/5 x 25/29) + (3/5 x 25/29)
= (50/145) + (75/145)
= 125/145

b) (5/2 x 3/7) - (3/14 : 6/7)
= 15/14 - (3/14 x 7/6)
= 15/14 - 1/2
= (30/28) - (14/28)
= 16/28
= 4/7

c) (15/4 : 5/12) - (6/5 : 11/15)
= (15/4 x 12/5) - (6/5 x 15/11)
= 180/20 - 90/55
= 9 - 18/11
= (99/11) - (18/11)
= 81/11
= 7 4/11

a) (2/3) + (20/21 x 3/2 x 7/5)
= 2/3 + (60/210)
= 2/3 + 2/7
= (14/21) + (6/21)
= 20/21

b) (5/17 x 21/32 x 47/24 x 0)
= 0

c) (11/3 x 26/7) - (26/7 x 8/3)
= (286/21) - (208/21)
= 78/21
= 3 9/21
= 3 3/7

a) (25/8) : x = 5/16
=> (25/8) x (16/5) = x
=> 4 = x

b) x + (7/15) = 6/15
=> x = (6/15) - (7/15)
=> x = -1/15

c) x : (28/49) = 7/12
=> x x (49/28) = 7/12
=> x = (7/12) x (28/49)
=> x = 1/2

a) 6 x x = (5/8) : (3/4)
=> 6x = (5/8) x (4/3)
=> 6x = 20/24
=> 6x = 5/6
=> x = (5/6) / 6
=> x = 5/36

câu,b,không,đủ,thông,tin,nhan,bạn.

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