\(112\cdot35+112\cdot65+800\)

\(=112\cdot\left(35+65\right)+800\)

\(=112\cdot100+800\)

\(=11200+800\)

\(=12000\)

a)  − 105 + − 25 + ( − 105 ) + 50  

= 105 + 25 + ( - 105) + 50

= [105 + ( -105)] + ( 25 + 50 )

= 0 + 75 = 75

b)  465 + − 38 + − 465 − 12 − − 42

= 465 + ( - 38) + ( -465) – 12 – 42

= [ 465 + (- 465) ] – ( 12 + 42 )

= 0 – 54 = 0 + ( -54 ) = -54

c)  65. − 19 + − 19 .24 + − 19 .11

= ( - 19) . ( 65 + 24 + 11 )

= ( -19) . 100 = -1900

d)  − 3 2 + 2 3 − − 5 2 + 4 3

= 9 + 8 – 25 + 64 = 56

a,(-65) +54-13              b,135-35:[(-3)+|-8|]                c,(-815)-[95-815+(-45)]

=(-11)-13                       =135-35:[(-3)+8]                  =(-815)-[95-770]

=-24                               =135-35:5                           =(-815)-(-675)

                                      =135-7                                 =-1490

                                      =128

\(a,=73.\left(34+1+65\right)=73.100=7300\\ b,=-\left(45+35\right)=-80\\ c,=299-6\left(14:5-3\right)=299-6\left(-\dfrac{1}{5}\right)=299+\dfrac{6}{5}=\dfrac{1501}{5}\)

1.
a) 73.34+73+73.65
= 73.34+73.1+73.65 (bạn có thể thêm bước này nếu bạn muốn)
= 73.(34+1+65)
= 73.100
= 7300
b) (-45)+(-35)
= -80 (vì trừ cộng trừ ra trừ)
c) 299-6[(12+2):5-3]
= 299-6(14:2)
= 299-6.7
= 299-42
= 257

Cô Hoài ơi, cô trả lời tin nhắn em với ạ!

a, (-25) + 276 - (276 - 25)

= (-25) + 276 - 276 + 25

= [ (-25) + 25] - (276 - 276)

= 0 - 0

 = 0

b, 24 x 46 + 24 x 53 + 24 

= 24 x ( 46 + 53 + 1)

= 24 x 100

= 2400

c, 145 + 20 - 45 + 180

= (145 - 45) + (20 + 180)

= 100 + 200

= 300

d; 12 x 36 + 12 x 65 - 12

= 12 x ( 36 + 65  - 1)

= 12 x (100)

= 1200

a) (-37) + 14 + 26 + 37

= [(-37) + 37] + (14 + 26)

= 0 + 40 = 40

b) (-24) + 6 + 10 + 24

= [(-24) + 24] + (10 + 6)

= 0 + 16 = 16

c) 15 + 23 + (-25) + (-23)

= [15 + (-25)] + [23 + (-23)]

= (-10) + 0 = -10

d) 60 + 33 + (-50) + (-33)

= [60 + (-50)] + [33 + (-33)]

= 10 + 0 = 10

e) (-16) + (-209) + (-14) + 209

= [(-16)  + (-14)] + [(-209) + 209]

= (-30) + 0 = -30

f) \(-3^2+\left(-54\right)\div\left[\left(-2\right)^8+7\right]\times\left(-2\right)^2\\ =\left(-9\right)+\left(-54\right)\div263\times4\\ =\left(-9\right)+\dfrac{-216}{263}=\dfrac{-2583}{263}\)

a. \(\left[\left(-37\right)+37\right]+\left(14+16\right)\) = 30 

B. \(\left[\left(-24\right)+24\right]+\left(10+6\right)\) = 16

C. \(\left[\left(-23\right)+23\right]+\left(15-23\right)\)= -8

d. \(\left[33-33\right]+\left(60-50\right)\) = 10

e. \(\left(209-209\right)+\left(-16-14\right)\)= -30

4a) \(\frac{x}{36}=\frac{3}{4}\)

\(\Rightarrow\frac{x}{36}=\frac{27}{36}\)

\(\Rightarrow x=27\)

4b) 33 + x = 71 - 26

33 + x = 45

x = 45 - 33

x = 12

4c) x * (3,5 + 1,5) = 10

x * 5 = 10

x = 10 ; 5 = 2

4,

\(a,\frac{x}{36}=\frac{24}{32}\)

\(=>\frac{x}{36}=\frac{3}{4}=\frac{27}{36}\)

\(=>x=27\)

\(b,71-\left(33+x\right)=26\)

\(=>-\left(33+x\right)=26-71=-45\)

\(=>33+x=45\)

\(=>x=12\)

\(c,3,5\cdot x+1,5\cdot x=10\)

\(>x\cdot\left(3,5+1,5\right)=10\)

\(=>x\cdot5=10\)

\(=>x=2\)

. là nhân nha

4. 

a) x/36 = 24/32

24/32 = 3/4 = 27/36

=> x = 27

b) 71 - ( 33 + x ) = 26

33 + x = 71 - 26

33 + x = 45

x = 45 - 33

x = 12

c) 3, 5 . X + 1, 5 . x = 10

x( 3, 5 + 1, 5 ) = 10

x . 5 = 10

x = 10 : 5

x = 2

5.

a) 4, 63 . 7, 8 + 7, 8 + 7, 8 . 4, 32

= 7, 8. ( 4, 63 + 4, 32 + 1 )

= 7, 8 . 9, 95

= 77, 61

b) 35 . 34 + 35 . 86 + 65 . 75 + 65 . 45

= 35( 34 + 86 ) + 65( 75 . 45 )

= 35 . 120 + 65 . 120

= 120 . ( 35 + 65 )

= 120 . 100

= 12 000

\(=\dfrac{9^3\cdot\left(2^3\cdot3+45\right)}{9^3}=8\cdot3+45=69\)

hợp lí nhất là tính trong ngoặc trước:)

a) 1125 - (374 + 1125) + (-65 + 374)

= 1125 - 374 - 1125 + (-65) + 374

= (1125 - 1125) + (-374 + 374) + (-65)

= 0 + 0 + (-65)

= -65

b) -23. 63 + 23 . 21 - 58 . 23

= 23 .(-63) + 23 . 21 - 58 . 23

= 23 . [(-63) + 21 - 58]

= 23 . (-100)

= -2300

c) -2003 + (-21 + 75 + 2003)

= -2003 + (-21) + 75 + 2003

= (-2003 + 2003) + (-21) + 75

= 0 + 54

= 54

d) 942 - 2567 + 2563 - 1942

= (942 - 1942) + (-2567 + 2563)

= -1000 + (-4)

= -1004

e) 12 - 12 + 11 + 10 - 9 + 8 - 7 + 5 - 4 + 3 + 2 - 1

= 0 + 11 + 1 + 1 + 1 + 3 + 1

= 18