Question

(2x+3/5)^2-9/25=0

3(3x-1)^3+1/9=0

nêu cách làm

Answer 1

a)2x+3/5=3/5

x=0

b)3

Answer 2

(2x+3/5)^2-9/25=0

<=> (2x+3/5)² = 9/25

<=> 2x+3/5 = + 3/5

TH1 : 2x+3/5 = 3/5

<=> x =(3/5 -3/5 ) :2 =0

TH2 : 2x+3/5 = -3/5

<=> x = ( -3/5 -3/5) :2 = -3/5

3(3x-1)^3+1/9=0

<=> 3(3x-1)^3 = -1/9

<=> (3x-1)^3  = -1/9 :3 = -1/27

<=> 3x-1 = -1/3

<=> 3x = -1/3 +1 = 2/3

<=> x = 2/3 :3 =2/9

Answer 3

\(\Leftrightarrow\left(\frac{2x+3}{5}\right)^2=\frac{9}{25}\)

\(\Rightarrow\frac{2x+3}{5}=\sqrt{0.36}\)

=>\(\frac{2x+3}{5}=0.6=\frac{2x+3}{5}=\frac{3}{5}\)

=>5(2x+3)=3*5

=>10x+3=15

=>10x=12

=>x=\(1\frac{1}{5}\)

Answer 4

(2x+3/5)^2=0+9/25=9/25=(3/5)^2 =>2x+3/5=3/5 =>2x=3/5-3/5=0 =>2x=0 =>x=0:2=0

3(3x- 1)^3=0- 1/9= -1/9 =>(3x- 1)^3= -1/9:3= -1/27 =>3x- 1= -1/3 =>3x= -1/3+1=2/3 =>x=2/9