Học sinh nhẩm và ghi kết quả như sau :

4000 – ( 2000 – 1000 ) = 3000

4000 – 2000 + 1000 = 3000

8000 – 4000 x 2 = 0

(8000 – 4000) x 2 = 8000

trả lời:

4000 -(2000 - 1000)

= 3000

4000 -2000 + 1000

= 3000

8000 - 4000 x 2

=0

( 8000 - 4000 ) x2

= 8000

4000 – (2000 – 1000) =3000

4000 – 2000 + 1000 =3000

8000 – 4000 x 2 =0

(8000 – 4000) x 2 =8000

x- 1000 = 2 

x = 1000 + 2

x = 1002

X-1000=2000:1000

X-1000=2

X=2+1000

X=1002

X-1000=2000:1000

X-1000=2

X=2+1000

X=1002

đặt x^1000=m,y^1000=n

m+n=a

m²+n²=2b/3 =>a²=2b/3+2mn =>mn=a²-2b/3

m⁵+n⁵=c/36 <=>(n+m)[(m+n)⁴-5mn(m+n)²+5m²n²]=c/36

<=>a.[a⁴-5(a²-2b/3)a²+5(a²-2b/3)² ]=c/36 <=>a(a⁴-10a²b/3+20b²/9)=c/36 <=>a(9a⁴-30a²b+20b²)=c/4

\(bx^2=ay^2\Rightarrow\dfrac{x^2}{a}=\dfrac{y^2}{b}=\dfrac{x^2+y^2}{a+b}=\dfrac{1}{a+b}\)

\(\Rightarrow\left(\dfrac{x^2}{a}\right)^{1000}=\left(\dfrac{y^2}{b}\right)^{1000}=\left(\dfrac{1}{a+b}\right)^{1000}\)

\(\Rightarrow\dfrac{x^{2000}}{a^{1000}}=\dfrac{y^{2000}}{b^{1000}}=\dfrac{1}{\left(a+b\right)^{1000}}\)

\(\Rightarrow\dfrac{x^{2000}}{a^{1000}}+\dfrac{y^{2000}}{b^{1000}}=\dfrac{1}{\left(a+b\right)^{1000}}+\dfrac{1}{\left(a+b\right)^{1000}}=\dfrac{2}{\left(a+b\right)^{1000}}\)

4000 + X = 6000

X = 6000 - 4000

X = 2000

tk nhé 

ai tk mình tk lại

x = 2000

k mình nha

X=6000-1000-1000-2000

x=2000

1000 + 1000 + 2000 + X = 12000

2000 + 2000 + X = 12000

4000 + X = 12000

X = 12000 - 4000

X = 8000

1000+1000+2000+X= 12000

                40000+X=12000

                            X= 12000-4000

                            X=8000

4000 + X = 12 000

           X = 12 000 - 4000

           X = 8000

tk nhé

5000 + X = 10 000

           X = 10 000 - 5000

           X = 2000

tk nhe

mình đang cần điểm hỏi đáp

cảm ơn

ok 5000

1000+1000+1000+2000+x=10000

(1000+1000+1000+2000)+x=10000

5000+x=10000

x=10000-5000

x=5000

=>x=5000

5000 + 100 = 5100

7400 - 400 = 7000

2000 3 + 600 = 6600

8000 : 2 + 2000 = 6000

6000 - (5000 - 1000) = 2000

6000 - 5000 + 1000 = 2000

7000 - 3000 x 2 = 1000

(7000 - 3000) x 2 = 8000

5000 + 100 = 5100

7400 - 400 = 7000

2000 3 + 600 = 6600

8000 : 2 + 2000 = 6000

6000 - (5000 - 1000) = 2000

6000 - 5000 + 1000 = 2000

7000 - 3000 x 2 = 1000

(7000 - 3000) x 2 = 8000

5000 + 100 = 5100

7400 - 400 = 7000

2000 3 + 600 = 6600

8000 : 2 + 2000 = 6000

6000 - (5000 - 1000) = 2000

6000 - 5000 + 1000 = 2000

7000 - 3000 x 2 = 1000

(7000 - 3000) x 2 = 8000

Đặt \(a=x^{1000},b=y^{1000}\)
\(\Rightarrow a+b=6,912\) và \(a^2+b^2=33,76244.\)
Ta có \(\text{a+b= 6,912}\)
\(\Rightarrow\) \(\left(a+b\right)^2=6,912^2\)
\(\Leftrightarrow \)\(a^2+2ab+b^2=47,775744\)
\(\Leftrightarrow ab=\frac{47,775744-30,76244}{2}\)
\(\Leftrightarrow ab=8,506052\)
\(\Leftrightarrow ab(a+b)=58,797978624\)
Ta lại có \(a^3+b^3+ab(a+b)=(a+b)(a^2+b^2)\)
\(\Leftrightarrow \)\(a^3+b^3=174,5680067\)
Vậy \(x^{3000}+y^{3000}=174,5680067\)