\(\frac{1}{3}x-1.2x-\frac{2}{23}.\left(\frac{-11}{12}+\frac{5}{6}-\frac{7}{8}\right)-\frac{1}{8}=-11\frac{2}{3}+12\frac{7}{8}\)

\(\Leftrightarrow\frac{1}{3}x-\frac{6}{5}x-\frac{2}{23}.\frac{-23}{24}-\frac{1}{8}=\frac{-35}{3}+\frac{103}{8}\)

\(\Leftrightarrow\frac{-13}{15}x+\frac{1}{12}-\frac{1}{8}=\frac{29}{24}\)

\(\Leftrightarrow\frac{-13}{15}x-\frac{1}{24}=\frac{29}{24}\)

\(\Leftrightarrow\frac{-13}{15}x=\frac{5}{4}\)

\(\Leftrightarrow x=\frac{-75}{52}\)

Vậy \(x=\frac{-75}{52}\)

1/3x-1/2x-2/23.(-11/12+5/6-7/8)-1/8=-31/3+103/8

1/3x-1,2x-2/23.(-11/12+5/6-7/8)-1/8=61/24

1/3x-1,2x-2/23.-23/24-1/8=61/24

1/3x-1,2x-1/12-1/8=61/24

1/3x-1,2x+1/24=61/24

x.(1/3-1,2)+1/24=61/24

x.-13/15+1/24=61/24

x.-33/40=61/24

x=61/24:-33/40

x=61/24×-40/33

x=-305/99

vậy x=-305/99

a: =4x^2-4x+1+9

=(2x-1)^2+9>=9

Dấu = xảy ra khi x=1/2

b: =2(x^2+3x)

=2(x^2+3x+9/4-9/4)

=2(x+3/2)^2-9/2>=-9/2

Dấu = xảy ra khi x=-3/2

c: =x^2-x+1/4-1/4

=(x-1/2)^2-1/4>=-1/4

Dấu = xảy ra khi x=1/2

a. A=4x-x²+3= 7-(x²-4x+4)=7-(x-2)²

Nhận thấy -(x-2)²\(\le0\forall x\)

=> 7-(x-2)²\(\le7\forall x\)

Dấu "=" xảy ra khi x-2=0=>x=2

Vậy max A=7 <=>x=2

b. B= -x²+6x-11= -2-(x²-6x+9)=-2-(x-3)²

Nhận thấy -(x-3)²\(\le0\forall x\)

=> -2-(x-3)² \(\le-2\forall x\)

Dấu "=" xảy ra khi x-3=0 => x=3

Vậy max B=-2 <=> x=3

bn đang nằm mơ hay sao jậy

ừ :v t đang mơ đấy..nên đừng phá để t mơ tiếp

A = |x-1| + x² +3

Nhận xét:

     \(\text{| x-1 |}\ge0\)

     \(x^2\ge0\)

=> A = |x-1| + x² +3 \(\le\) 3 

Vậy min_A = 3

sai r bn ak

lm tek này ker:

xét 2TH

+,x>=1 thì A=x-1+x^2+3=x^2+x+2>=1+1+2=4    (1)

+,x<=1 thì A=1-x+x^2+3=x^2-x+4=(x-1/2)^2+15/4    (2)

so sánh (1) và (2)=>minA=15/4 khi x=1/2

Chị cũng là fan của BTS à

Chị hâm mộ V đúng không

Em hâm mộ JungKook

Giải phương trình

a, 5x(x-4)-5x² = 2 (11-x)

\(\Leftrightarrow5x^2-20x-5x^2=22-2x\)

\(\Leftrightarrow-18x=22\)

\(\Leftrightarrow x=\frac{-22}{18}\)

b, \(\frac{3}{x-3}-\frac{2}{x+3}=\frac{4x}{x^2-9}\left(x\ne\pm3\right)\)

\(\Leftrightarrow\frac{3\left(x+3\right)}{\left(x-3\right)\left(x+3\right)}-\frac{2\left(x-3\right)}{\left(x-3\right)\left(x+3\right)}=\frac{4x}{x^2-9}\)

\(\Rightarrow3x+9-2x+6=4x\)

\(\Leftrightarrow3x=15\)

\(\Leftrightarrow x=5\left(tm\right)\)

Kl: a,.........

b,.........

a) \(\left(x-11\right)+\frac{3x}{x-11}=3+\frac{33}{x-11}\)

\(\Leftrightarrow x+\frac{3x}{x-11}-\frac{33}{x-11}=14\)

\(\Leftrightarrow x^2-11x+3x-33=14x-154\)

\(\Leftrightarrow x^2-22x+121=0\)

\(\Leftrightarrow\left(x-11\right)^2=0\Leftrightarrow x=11\)

Vậy .......

b) \(\frac{7-2x}{x-1}=\frac{1-4x}{x+2}\Leftrightarrow\left(7-2x\right)\left(x+2\right)=\left(1-4x\right)\left(x-1\right)\)

\(\Leftrightarrow7x-2x^2+14-4x=x-4x^2-1+4x\)

\(\Leftrightarrow2x^2=-15\)(vô lí)

Vậy pt vô nghiệm

c) \(\frac{3-2x}{x+1}=2+\frac{1-4x}{x-2}\)

\(\Leftrightarrow\left(3-2x\right)\left(x-2\right)=2\left(x+1\right)\left(x-2\right)+\left(1-4x\right)\left(x+1\right)\)

\(\Leftrightarrow3x-2x^2-6x+4x=2x^2+2x-4x-4+x-4x^2+1-4x\)

\(\Leftrightarrow6x=-3\Leftrightarrow x=-\frac{1}{2}\)

Vậy.........

(gửi trước 3 câu)

d) \(\frac{109x-4}{111x+1}-1=0\Leftrightarrow109x-4=111x+1\Leftrightarrow2x=-5\Leftrightarrow x=-\frac{5}{2}\)

Vậy x=-5/2

e) \(\frac{x^2-7}{x}=x-\frac{1}{2}\Leftrightarrow\frac{x^2-7}{x}-\frac{x^2}{x}=-\frac{1}{2}\Leftrightarrow-\frac{7}{x}=\frac{1}{2}\Leftrightarrow x=-14\)

f) \(\frac{x+1}{x+2}=3\Leftrightarrow x+1=3x+6\Leftrightarrow2x=7\Leftrightarrow x=\frac{7}{2}\)

d) \(\frac{109x-4}{111x+1}=1\)

\(\Rightarrow\frac{109x-4}{111x+1}=1\)

\(\Rightarrow109x-4=111x+1\)

\(\Rightarrow-2x=5\)

\(\Rightarrow x=-2,5\)

Vậy x = -2,5

e) \(\frac{x^2-7}{x}=x-\frac{1}{2}\)

\(\Rightarrow\frac{x^2-7}{x}=\frac{2x-1}{2}\)

\(\Rightarrow\left(x^2-7\right)2=x\left(2x-1\right)\)

\(\Rightarrow2x^2-14=2x^2-x\)

\(\Rightarrow x=14\)

Vậy x = 14

f) \(\frac{x+1}{x+2}=3\)

\(\Rightarrow x+1=3\left(x+2\right)\)

\(\Rightarrow x+1=3x+6\)

\(\Rightarrow2x=-5\)

\(\Rightarrow x=-2,5\)

Vậy x = -2,5