\(x+360=500-200\)

\(x+360=300\)

             \(x=300-360\)

             \(x=-60\)

x + 360 = 500 - 200

x + 360 = 300

x          = 300 - 360

x          = - 60

x + 360 = 500 - 200

X          =300 - 360=-60

Đáp số:-60

x+360=400

x=400-360

x=40

vậy......k mình nha...kb nữa...^_^...thanks♥

x + 360 = 400

x          = 400 - 360

x          = 40

Vay x =40

ai k mik mik k lai

x + 360 = 400

          x = 400 - 360

          x = 40                 k mk nha mina~~

x + 200 = 400 - 200                                                                              x - 200 = 400 - 300

x + 200 = 200                                                                                       x - 200 = 100

x           = 200 - 200                                                                             x             = 100 + 200

x           = 0                                                                                           x             = 300

k nhé  Chicchana Mune No Tokimeki thuy linh

X = 0 

X = 300

x + 200 = 400 - 200

x + 200 = 200

x          = 200 - 200

x          = 0

x - 200 = 400 - 300

x - 200 = 100

x          = 100 + 200

x          = 300

\(\dfrac{360}{x}-\dfrac{400}{x+1}=1\) (ĐK: \(x\ne0,x\ne-1\))

\(\Leftrightarrow\dfrac{360\left(x+1\right)}{x\left(x+1\right)}-\dfrac{400x}{x\left(x+1\right)}=\dfrac{x\left(x+1\right)}{x\left(x+1\right)}\)

\(\Leftrightarrow360\left(x+1\right)-400x=x\left(x+1\right)\)

\(\Leftrightarrow360x+360-400x=x^2+x\)

\(\Leftrightarrow-40x+360=x^2+x\)

\(\Leftrightarrow x^2+40x+x-360=0\)

\(\Leftrightarrow x^2+41x-360=0\)

\(\Rightarrow\Delta=41^2-4\cdot1\cdot\left(-360\right)=3121>0\)

\(\Rightarrow\left[{}\begin{matrix}x_1=\dfrac{-41+\sqrt{3121}}{2\cdot1}\approx7\left(tm\right)\\x_2=\dfrac{-41-\sqrt{3121}}{2\cdot1}\approx-48\left(tm\right)\end{matrix}\right.\)

\(\dfrac{360}{x}-\dfrac{400}{x+1}=1\)

Điều kiện: \(x\ne0;x\ne-1\)

PT \(\Leftrightarrow\dfrac{360\left(x+1\right)-400x}{x\left(x+1\right)}=1\)

\(\Rightarrow-40x+360=x\left(x+1\right)\)

\(\Leftrightarrow-40x+360=x^2+x\)

\(\Leftrightarrow x^2+41x-360=0\)

\(\Leftrightarrow x^2+2.\dfrac{41}{2}.x+\dfrac{1681}{4}=\dfrac{3121}{4}\)

\(\Leftrightarrow\left(x+\dfrac{41}{2}\right)^2=\left(\dfrac{\sqrt{3121}}{2}\right)^2\)

\(\Leftrightarrow x+\dfrac{41}{2}=\dfrac{\sqrt{3121}}{2}\) hoặc \(x+\dfrac{41}{2}=-\dfrac{\sqrt{3121}}{2}\)

\(\Leftrightarrow x=\dfrac{\sqrt{3121}}{2}-\dfrac{41}{2}\) hoặc \(x=-\dfrac{\sqrt{3121}}{2}-\dfrac{41}{2}\)

Vậy...

Vừa đếm thêm 100 000 (10 000; 1000; 10; 1) vừa điền vào chỗ chấm

a) 300 000; 400 000; 500 000;600 000; 700 000; 800 000.

b) 350 000; 360 000; 370 000; 380 000; 390 000; 400 000

c) 399 000; 399 100; 399 200;399 3000; 399 400; 399 500

d) 399 940; 399 950; 399 960;399 970; 399 980; 399 990

e) 456 784; 456 785; 456 786; 456 787; 456 788; 456 789

\(\left(\dfrac{1}{200}+\dfrac{1}{300}+\dfrac{1}{400}+...+\dfrac{1}{1000}\right).1.2.3.4.5\).\(\left(\dfrac{1}{120}-\dfrac{1}{180}-\dfrac{1}{360}\right)\)

Xét \(\left(\dfrac{1}{120}-\dfrac{1}{180}-\dfrac{1}{360}\right)\) ta có :

= \(\dfrac{1}{120}-\left(\dfrac{1}{180}+\dfrac{1}{360}\right)\) =\(\dfrac{1}{120}-\dfrac{1}{120}=0\)

Trong 1 tích nếu có 1 thừa số 0 thì tích đó bằng 0

Biểu thức trên có 1 thừa số 0 nên biểu thức trên bằng 0

Vừa đếm thêm 100 000 (10 000; 1000; 10; 1) vừa điền vào chỗ chấm

a) 300 000; 400 000; 500 000;600 000; 700 000; 800 000.

b) 350 000; 360 000; 370 000; 380 000; 390 000; 400 000

c) 399 000; 399 100; 399 200;399 3000; 399 400; 399 500

d) 399 940; 399 950; 399 960;399 970; 399 980; 399 990

e) 456 784; 456 785; 456 786; 456 787; 456 788; 456 789

300 000 ; 400 000 ; 500 000 ; 600 000 ; 700 000 ; 800 000 
350 000 ; 360 000 ; 370 000 ; 380 000 ; 390 000 ; 400 000
399 000 ; 399 100 ; 399 200 ; 399 300 ; 399 400 ; 399 500

399 940 ; 399 950 ; 399 960 ; 399 970 ; 399 980 ; 399 990
456 784 ; 456 785 ; 456 786 ; 456 787 ; 456 788 ; 456 789

\(\Leftrightarrow\left\{{}\begin{matrix}\dfrac{28}{25}x+\dfrac{28}{25}y=\dfrac{2016}{5}\\\dfrac{28}{25}x+\dfrac{11}{10}y=400\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=160\\x=200\end{matrix}\right.\)

\(\left\{{}\begin{matrix}x+y=360\\112\%x+110\%y=400\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x+y=360\\\dfrac{28x}{25}+\dfrac{11y}{10}=400\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x+y=360\\\dfrac{56x}{50}+\dfrac{55y}{50}=400\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x+y=360\\\dfrac{56x+55y}{50}=400\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x+y=360\\56x+55y=20000\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x=200\\y=160\end{matrix}\right.\)