b, SSH: (30-20):1+1+11

    Tổng: (30+20)*11:2+275

Tạm thế đã

c, 64 * 25 + 35 * 25 + 25

= 64 * 25 + 35 * 25 + 25 * 1

= (64 + 35 + 1) * 25

= 100 * 25

= 2500

Phương pháp giải:

- Đặt tính: Viết phép tính sao cho các chữ số cùng hàng thẳng cột với nhau.

- Tính: Cộng hoặc trừ các số lần lượt từ phải sang trái. 

Lời giải chi tiết:

46,3 

46 phút 23 giây

46 phút 23 giây

a) $420-(71+420)$

$=420-71-420$

$=-71$

b) $(35-120)+(120+410-35)$

$=35-120+120+410-35$

$=(35-35)+(-120+120)+410$

$=410$

c) $(320-15+49)-(85-51)$

$=320-15+49-85+51$

$=320+(-15-85)+(49+51)$

$=320+(-100)+100$

$=320$

d) $-(312+59)-(41+400+88)$

$=-312-59-41-400-88$

$=(-312-88)+(-59-41)-400$

$=-400+(-100)-400$

$=-500-400$

$=-900$

e) $(430-731)-(-731+430-56)$

$=430-731+731-430+56$

$=(430-430)+(-731+731)+56$

$=56$

f) $(1352-47)-(53-1000+1352)$

$=1352-47-53+1000-1352$

$=(1352-1352)+(-47-53)+1000$

$=(-100)+1000$

$=1000-100$

$=900$

h) $(-42)-(370+58)-(120-370)$

$=-42-370-58-120+370$

$=(-42-58)+(-370+370)-120$

$=-100-120$

$=-220$

$Toru$

Chịu

dễ

Câu 1: 

a. $=-(35+65)+(22+88)=-100+110=110-100=10$

c. $=58(26+74)=58.100=5800$

b. $=29(38+63-1)=29.100=2900$

Câu 2:

a. $3x+9=30$

$3x=30-9=21$

$x=21:3=7$

a.35 x 34 + 35 x 38 + 65 x 75 + 45 x 65

= 35 x (34 + 38) + 65 x 75 + 65 x 45

= 35 x     72      + 65 x (75+45)

= 35 x 72 + 65 x 120

= 35 x 72 + 65 x (72 + 48)

= 35 x 72 + 65 x 72 + 65 x 48

= (35+65) x 72 + 65  x 48

=   100 x 72 + 65 x 48

=      7200   +    3120

=           10320

b.39 x 8 + 60 x 2 + 21 x 8

=39 x 8 + 15 x 4 x 2 +21 x 8

= 39 x 8 + 15 x 8 + 21 x 8

=(39 + 15 + 21) x 8

=      75            x 8

=             600

c.58 x 75 + 58 x 50 - 58 + 25

= 58 x 75 + 58 x 50 - 58 x 1 + 25

= 58 x(75+50-1)+25

= 58 x   124     + 25

=    7192          + 25

=              7217

d.125 x 98 - 125 x 46 - 52 x 25

= 25 x 5 x 98 - 25 x 5 x 46 - 25 x 52

= 25 x 490 - 25 x 230 - 25 x 52

= 25 x (490 - 230 - 52)

= 25 x      208

=       5200

ham mo chi qua

25 + 36 + 98 + 58 + 26 + 35

= 61 + 98 + 58 + 26 + 35

= 159 + 58 + 26 + 35

= 217 + 26 + 35

= 243 + 35

= 278

k mk nha

- Ôi dễ vãi ~~

Ta có:

\(\frac{2^{35}.45^{25}.13^{22}.35^{16}}{9^{26}.65^{22}.28^{17}.25^9}=\frac{2^{35}.\left(9.5\right)^{25}.13^{22}.\left(5.7\right)^{16}}{9^{26}.\left(5.13\right)^{22}.\left(7.4\right)^{17}.\left(5.5\right)^9}\)

\(=\frac{2^{35}.9^{25}.5^{25}.13^{22}.5^{16}.7^{16}}{9^{26}.13^{22}.5^{22}.7^{17}.4^{17}.5^9.5^9}\)

\(=\frac{2^{35}.5^3}{9.4^{17}.5^2.7}\)

\(=\frac{2^{35}.5}{9.4^{17}.7}\)

\(=\frac{2^{35}.5}{9.2^{34}.7}\)

\(=\frac{2.5}{9.7}\)

\(=\frac{10}{63}\)

p/s: - Ko chắc ~

\(\frac{2^{35}.45^{25}.13^{22}.35^{16}}{9^{26}.65^{22}.28^{17}.25^9}=\frac{2^{35}.5^{25}.9^{25}.13^{22}.5^{16}.7^{16}}{9^{26}.5^{22}.13^{22}.4^{17}.7^{17}.5^9.5^9}=\frac{2^{35}.5^3.5^7}{9.\left(2^2\right)^{17}.7.5^9}=\frac{2^{35}.5^3}{9.2^{34}.7.5^2}=\frac{2.5}{9.7}=\frac{10}{63}\)