Giải:

Ta có: \(3\left(x-1\right)=2\left(y-2\right)\Rightarrow\frac{x-1}{2}=\frac{y-2}{3}\)

\(4\left(y-2\right)=3\left(z-3\right)\Rightarrow\frac{y-2}{3}=\frac{z-3}{4}\)

\(\Rightarrow\frac{x-1}{2}=\frac{y-2}{3}=\frac{z-3}{4}\)

Áp dụng tính chất dãy tỉ số bằng nhau ta có:
\(\frac{x-1}{2}=\frac{y-2}{3}=\frac{z-3}{4}=\frac{2x-2}{4}=\frac{3y-6}{9}=\frac{z-3}{4}=\frac{2x-2+3y-6+z-3}{4+9+4}=\frac{\left(2x+3y+z\right)-\left(2+6+3\right)}{17}\)

\(=\frac{50-11}{17}=\frac{39}{17}\)

+) \(\frac{x-1}{2}=\frac{39}{17}\Rightarrow x-1=\frac{78}{17}\Rightarrow x=\frac{95}{17}\)

+) \(\frac{y-2}{3}=\frac{39}{17}\Rightarrow y-2=\frac{117}{17}\Rightarrow y=\frac{151}{17}\)

+) \(\frac{z-3}{4}=\frac{39}{17}\Rightarrow z-3=\frac{156}{17}\Rightarrow z=\frac{207}{17}\)

Vậy bộ số \(\left(x;y;z\right)\) là \(\left(\frac{95}{17};\frac{151}{17};\frac{207}{17}\right)\)

Giải:
Ta có: \(3\left(x-1\right)=2\left(y-2\right)\Rightarrow\frac{x-1}{2}=\frac{y-2}{3}\)

\(4\left(y-2\right)=3\left(z-3\right)\Rightarrow\frac{y-2}{3}=\frac{z-3}{4}\)

\(\Rightarrow\frac{x-1}{2}=\frac{y-2}{3}=\frac{z-3}{4}\)

Áp dụng tính chất dãy tỉ số bằng nhau ta có:
\(\frac{x-1}{2}=\frac{y-2}{3}=\frac{z-3}{4}=\frac{2x-2}{4}=\frac{3y-6}{9}=\frac{2x-2+3y-6}{4+9}=\frac{\left(2x+3y\right)-\left(2+6\right)}{13}=\frac{50-8}{13}=\frac{42}{13}\)

+) \(\frac{x-1}{2}=\frac{42}{13}\Rightarrow x-1=\frac{84}{13}\Rightarrow x=\frac{97}{13}\)

+) \(\frac{y-2}{3}=\frac{42}{13}\Rightarrow y-2=\frac{126}{13}\Rightarrow y=\frac{152}{13}\)

+) \(\frac{z-3}{4}=\frac{42}{13}\Rightarrow z-3=\frac{168}{13}\Rightarrow z=\frac{207}{13}\)

Vậy bộ số \(\left(x;y;z\right)\) là \(\left(\frac{97}{13};\frac{152}{13};\frac{207}{13}\right)\)

a/ M = |3x+8,4|-14,2

Ta thấy:\(\left|3x+8,4\right|\ge0\)

\(\Rightarrow\left|3x+8,4\right|-14,2\ge0-14,2=-14,2\)

\(\Rightarrow M\ge0\)

Dấu = khi x=-2,8

Vậy Mmin=-2,8 khi x=-2,8

b/cách lm mk chưa nghĩ ra nhưng ra

Nmin=26,5 khi x=-1,5

c)P =|x-2012|+|x-2011|

áp dụng Bđt |a|+|b|>=|a+b| ta có:

\(\left|x-2012\right|+\left|x-2011\right|\ge\left|x-2012+2011-x\right|=1\)

\(\Rightarrow P\ge1\)

Dấu = khi \(x\in\left[2011;2012\right]\)

Vậy Pmin=1 khi \(x\in\left[2011;2012\right]\)

Tks Thắq nhìu nké

a

\(25+\left(x-5\right)=-15\\ x-5=\left(-15\right)-25=\left(-40\right)\\ x=\left(-40\right)+5=-35\)

25 + (x-5) = -415 - (-400)
25 + (x-5) =     -15
         x-5  =-15 - 25
         x-5  =   -40
         x     = -40 + 5
         x     =     -35

Đặt A = 5 × 6 + 6 × 7 + 7 × 8 + ... + 99 × 100

3A = 5 × 6 × (7 - 4) + 6 × 7 × (8 - 5) + 7 × 8 × (9 - 6) + ... + 99 × 100 × (101 - 98)

3A = 5 × 6 × 7 - 4 × 5 × 6 + 6 × 7 × 8 + 7 × 8 × 9 - 6 × 7 × 8 + .... + 99 × 100 × 101 - 98 × 99 × 100

3A = 99 × 100 × 101 - 4 × 5 × 6

3A = 3 x (33 × 100 × 101 - 4 × 5 × 2)

A = 33 × 100 × 101 - 4 × 5 × 2

A = 333300 - 40

A = 333260

333260

333260

\(\left(x+1\right)+\left(x+1\right)+\left(x+1\right)+\left(x+1\right)+\left(x+1\right)=55\)

\(x+1+x+1+x+1+x+1+x+1=55\)

\(5x+5=55\)

\(5x=55-5\)

\(5x=50\)

\(x=50:5\)

\(x=10\)

TL:

X=10

Vì (10+1)+(10+1)+(10+1)+(10+1)+(10+1)=55

@hiếu

~HT~

= 2364 x (37 + 63) 

= 2364 x 100

= 236400

= 2364 x (37 + 63) 

= 2364 x 100

= 236400

tick ch mình với ạ

2364 + 37 x 2364 + 63

= 2364 x (37 + 63) 

= 2364 x 100

= 236400

x + 32 = ( - 15 ) 

x = ( - 15 ) - 32 

x = - 47 

Vậy x = - 47 

x+32=-15

=> x = -15 -32

=> x= - 47

Vậy x=-47

Học tốt

Trl:

x + 32 = (-15)

=> x = (-15) - 32

=> x = -47

Vậy x = -47

Hc tốt