K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

15 tháng 7

bạn ơi câu này cơ

15 tháng 7

2641-356x5

=2641-1825

=816

22 tháng 12 2021

Chọn B

22 tháng 12 2021

C

9 tháng 11 2018

a) x × 5 = 50 – 15

x × 5 = 35

x = 35 : 5

x = 7

b) x : 4 = 38 – 33

x : 4 = 5

x = 5 × 4

x = 20

c) x + 356 = 414 + 62

x + 356 = 476

x = 476 – 356

x = 120

d) x : 4 = 2 × 3

x : 4 = 6

x = 6 × 4

x = 24

7 tháng 4 2017

Đặt tính rồi tính: 

a/ 493 + 325= 818

b/ 928  - 356= 572

c/ 186 x 5= 930

d/ 639 : 3= 213

29 tháng 12 2022

789. 2- 56+ (-95)+111+261+498-215+49+1236-4591-56+4189+48+52-1000-500+230+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

= 1578- 56+ (-95)+111+261+498-215+49+1236-4591-56+4189+48+52-1000-500+230+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=1522+ (-95)+111+261+498-215+49+1236-4591-56+4189+48+52-1000-500+230+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=1427+111+261+498-215+49+1236-4591-56+4189+48+52-1000-500+230+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=1538+261+498-215+49+1236-4591-56+4189+48+52-1000-500+230+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=1799+498-215+49+1236-4591-56+4189+48+52-1000-500+230+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=2297-215+49+1236-4591-56+4189+48+52-1000-500+230+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=2082+49+1236-4591-56+4189+48+52-1000-500+230+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=2131+1236-4591-56+4189+48+52-1000-500+230+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=3367-4591-56+4189+48+52-1000-500+230+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=-1224-56+4189+48+52-1000-500+230+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=-1280+4189+48+52-1000-500+230+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=2909+48+52-1000-500+230+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=2957+52-1000-500+230+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=3009-1000-500+230+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=2009-500+230+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=1509+230+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=1739+32500-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=34239-5600+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=28639+2641+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=31280+853+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=32133+195-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=32328-564+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=31764+235+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=31999+4187+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=36186+9023177-5000000+562+159-90+459-420+562+235+489+71+12

=9059363-5000000+562+159-90+459-420+562+235+489+71+12

=4059363+562+159-90+459-420+562+235+489+71+12

=4059925+159-90+459-420+562+235+489+71+12

=4060084-90+459-420+562+235+489+71+12

=4059994+459-420+562+235+489+71+12 

=4060453-420+562+235+489+71+12 

=4060033+562+235+489+71+12 

=4060595+235+489+71+12

=4060830+489+71+12

=4061319+71+12=4061402

29 tháng 12 2022

ủa:q. rảnh v:))

8 tháng 9 2021

\(P\left(x\right)=\dfrac{4x^4+16x^3+56x^2+80x+356}{x^2+2x+5}\\ P\left(x\right)=\dfrac{4x^2\left(x^2+2x+5\right)+8x\left(x^2+2x+5\right)+20\left(x^2+2x+5\right)+256}{x^2+2x+5}\\ P\left(x\right)=4\left(x^2+2x+5\right)+\dfrac{256}{x^2+2x+5}\\ \ge2\sqrt{\dfrac{4\left(x^2+2x+5\right)\cdot256}{x^2+2x+5}}=2\sqrt{1024}=64\left(BĐTcosi\right)\)

Dấu \("="\Leftrightarrow4\left(x^2+2x+5\right)=\dfrac{256}{x^2+2x+5}\)

\(\Leftrightarrow x^2+2x+5=8\Leftrightarrow x^2+2x-3=0\Leftrightarrow\left[{}\begin{matrix}x=1\\x=-3\end{matrix}\right.\)

 

 

 

8 tháng 9 2021

P(x)=\(\dfrac{\text{(4x^2+8x^3+20x^2)+(8x^3+16x^2+40x)+(20x^2+40x+100)+256}}{x^2+2x+5}\)

      =(4x^2+8x+20x) +\(\dfrac{256}{x^2+2x+5}\)

áp dụng BĐT Cosi a+b≥\(2\sqrt{ab}\)

=>P(x)≥64

Dấu = xảy ra khi x=-1 hoặc x=3

 

HQ
Hà Quang Minh
Giáo viên
29 tháng 11 2023

a)

1 kg = 1 000 g      

1 000 g = 1 kg

b)

356 g + 400 g = 756 g          

1 000 g – 500 g = 500 g

8 g x 6 = 48 g

30 g : 5 = 6 g

23 tháng 3 2020

a, 1/2 x 356 + 45/10 x 356 + 356 x 50/10

= 356 x ( 1/2 + 45/10 + 50/10 )

= 356 x 10

= 3560

b, x+4 + x+6 + x+8 + x+12 = 1290

(x+x+x+x) + (4+6+8+12) = 1290

4x + 30 = 1290

4x = 1290 - 30

4x = 1260

x = 1260 : 4

x = 315

12 tháng 4 2020

 x+4+x+6+x+12=1290

x+ 4+6+12=1290

x+22=1290

x=1290-22

x=1268

16 tháng 7 2017

\(P=\dfrac{4x^4+16x^3+56x^2+80x+356}{x^2+2x+5}\)

\(=\dfrac{\left(4x^4+8x^3+20x^2\right)+\left(8x^3+16x^2+40x\right)+\left(20x^2+40x+100\right)+256}{x^2+2x+5}\)

\(=\left(4x^2+8x+20x\right)+\dfrac{256}{x^2+2x+5}\)

\(\ge2\sqrt{4\left(x^2+2x+5\right)\times\dfrac{256}{x^2+2x+5}}=64\)

Dấu "=" xảy ra khi x = 1 hoặc x = - 3

22 tháng 12 2021

356x41+356x35+356x23+356
=356x(41+35+23+1)
=356x100
=35600

22 tháng 12 2021

356*41+356*35+356*23+356

356*(41+35+23+1)

356*100=35600 :)))