a) \(250 + 250 × 2 = 250 + 500 = 750 \\ (250 + 250) × 2 = 500 × 2 = 1 000\)

b)\( 750 – 50 × 5 = 750 – 250 = 500\\ (750 – 50) × 5 = 700 × 5 = 3 500\)
c) \(210 × 4 – 4 × 210 = 840 – 840 = 0\\ 3 × (270 : 9) × 0 = 0\)

: Cho hàm số y = f(x) = (3m - 2)x
a, Tìm m biết điểm I(2; 8) thuộc đồ thị hàm số
b, Vẽ đồ thị hàm số với m vừa tìm đc, CMR: f(-2) + f(-4) = 3.f(-2)
a,điểm I(2; 8) thuộc đồ thị hàm số
=>8=(3m-2)2
<=>m=2
b,f(-2)=(2-3m)2 =>3f(-2)=6(2-3m)
f(-4)=(2-3m)4
=>f(-2)+f(-4)=6(2-3m)=3f(-2)

\(5\cdot\left(x-2\right)^3-3\cdot\left(x-2\right)^3=250\)

\(\left(x-2\right)^3\cdot\left(5-3\right)=250\)

\(\left(x-2\right)^3\cdot2=250\)

\(\left(x-2\right)^3=\dfrac{250}{2}\)

\(\left(x-2\right)^3=125\)

\(\left(x-2\right)^3=5^3\)

\(x-2=5\)

\(x=5+2\)

\(x=7\)

\(5.\left(x-2\right)^3-3\left(x-2\right)^3=250\)

\(\Leftrightarrow\left(x-2\right)^3.\left(5-3\right)=250\)

\(\Leftrightarrow\left(x-2\right)^3.2=250\)

\(\Leftrightarrow\left(x-2\right)^3=125\)

\(\Leftrightarrow\left(x-2\right)^3=5^3\)

\(\Leftrightarrow x-2=5\)

\(\Leftrightarrow x=7\)

( 500 x 9 - 250 x 2 x 9 ) x ( 1 + 2 + 3 .... +9 )

\(=9\times\left(500-250\times2\right)\times\left(1+2+...+9\right)\\ =9\times\left(500-500\right)\times\left(1+2+...+9\right)\\ =9\times0\times\left(1+2+...+9\right)=0\)

\(\left(500\cdot9-250\cdot2\cdot9\right)\cdot\left(1+2+3+...+9\right)\)

\(=\left(500\cdot9-500\cdot9\right)\left(1+2+3+...+9\right)\)

\(=0\cdot\left(1+2+3+...+9\right)=0\)

x + (x + 1) + (x + 2) + ... + (x + 250) = 0

\(\Leftrightarrow\) x + x + 1 + x + 2 + x + 3 + x + 4 + ... + x + 250 = 0

\(\Leftrightarrow\) 251x + (1 + 2 + 3 + 4 + ... + 250) = 0

\(\Leftrightarrow\) 251x + 31375 = 0

\(\Leftrightarrow\) 251x = -31375

\(\Leftrightarrow\) x = -125

Vậy S = {-125}

Chúc bn học tốt!!

 250 x 15 + 250 x 50 + 250 x 35.

= 250 x ( 15 + 50 + 35 ).

= 250 x 100

= 25000.

k mik nha!!

#Học tốt.

\(250\times15+250\times50+250\times35\)

\(=250\times\left(15+50+35\right)\)

\(=250\times100\)

\(=25000\)

 #hoktot<3#

Ta có:

      \(250\times15+250\times50+250\times35\)

\(=250\times\left(15+50+35\right)\)

\(=250\times100\)

\(=25000\)

( x - 25) x 17 = 34

=> x - 25 = 34 : 17

     x - 25 = 2

=> x = 2 + 25

     x = 27

145 + (150 - x) = 250

=> 150 - x = 250 - 145

     150 - x = 105

=> x = 150 - 105

     x = 45

(2x - 7) x 81 = 0

=> 2x - 7 = 0 : 81

    2x - 7 = 0

  => 2x = 7

   => x = 7 : 2 = 3,5

x - 90 : 15  = 32

=> x - 6 = 32

=> x = 32 + 6

    x = 38

520 - (x - 5) = 250 : 5

 => 520 - (x - 5) = 50

=> x - 5 = 520 - 50

   x - 5 = 470

=> x = 470 + 5

    x = 475

t i c k nhé!! 346457567684786896789

a ) \(\left(x-5\right).17=34\)

=> \(x-5=2\)

=> \(x=7\)

b ) \(145+\left(150-x\right)=250\)

=> \(150-x=105\)

=> \(x=150-105\)

=> \(x=45\)

c ) \(\left(2.x-7\right).81=0\)

=> \(2x-7=0\)

=> \(2x=7\)

=> \(x=\frac{7}{2}\)

d ) \(x-90:15=32\)

=> \(x-6=32\)

=> \(x=38\)

Mấy cái dấu chấm đó là nhân đó nhé

  2 x 5^x = 250 

        5 ^ x = 250 : 2 

         5^x  = 125 

         5^x    = 5^3 

=> x = 3

2 . 5^x = 250

5^x = 250 : 2 = 125

Mà 5³ = 125

=> x = 3