x(100%+20%)=7.2

x120%=720%

x=720%:120%

x=6

vậy////////

(40%+100%)x+20%=720%

140%x=720%-20%

140%x=700%

x=720%:140%

x=36/7

vậy x=/////////////

x﴾100%+20%﴿

=7.2 x120%

=720% x

=720%:120%

x=6 

ta có 

X x(8,75+1,25)=20

X x    10         =20    

X =20:10

X=2

8,75x X + 1,25 xX = 20

( 8,75+1,25) x X=20

10xX=20

X=20:10

X=2

8.75*x+1.25*x=20

(8.75+1.25)*x=20

10*x=20

x=20:10

x=2

bn l-ike cho mk trước đã

Ta có : A=20/11×13 + 20/13×15 +20/15×17+...+20/53×55

A = 10 ×( 2/11×13+2/13×15+...12/53×55)

A = 10 ×(1/11-1/13+1/13-1/15+1/15-1/17+...+1/53-1/55)

A = 10 × (1/11-1/55)

A =10 × 4/55

A = 8/11

x+20%*x=7,2

x(20%+1)=7,2

x(1/5+1)=7,2

x*6/5=7,2

x*1,2=7,2

x=7,2:1,2

x=6

x+20%*x=7,2

x(20%+1)=7,2

x(1/5+1)=7,2

x*6/5=7,2

x*1,2=7,2

x=7,2:1,2

x=6

TÔI CHỊU

X - 20% x X = 216

X - 20/100 x X = 216

X x (1 - 20/100) = 216

X x 4/5 = 216

X = 216 : 4/5

X = 270

(Tíck cho mình với nhé!)

x -20% x X = 216

x -1/5 x X=216

(1-1/5)x X =216

1x X - 1 x 1/5 =216

4/5 x X= 216

x = 216:4/5 =270

=>5(x-3)=20(x+1)

=>5x-15=20x+20

=>-15x=35

hay x=-7/3

\(x-\dfrac{3}{20}=x+\dfrac{1}{5}\)

\(\Leftrightarrow0=\dfrac{1}{5}+\dfrac{3}{20}\left(voli\right)\)

Vậy pt vô nghiệm

\(\Leftrightarrow\dfrac{x-3}{20}=\dfrac{4\left(x+1\right)}{20}\)

\(\Leftrightarrow x-3=4x+4\)

\(\Leftrightarrow3x=-7\Leftrightarrow x=-\dfrac{7}{3}\)

M={-16;-12;-8;-4;0;4;8;12;16}