c)\(\Leftrightarrow5x\left(x-3\right)-\left(x-3\right)=0\Leftrightarrow\left(5x-1\right)\left(x-3\right)=0\)

đến đây tự làm

a, <=> x.(x^2-4x+4) = 0

<=> x.(x-2)^2 = 0

<=> x=0 hoặc x-2=0

<=> x=0 hoặc x=2

b, <=> 5x^2-11x = -2

<=>5x^2-11x+2 =  0

<=>(5x^2-10x)-(x-2)=0

<=> (x-2).(5x-1)=0

<=>x-2=0 hoặc 5x-1=0

<=> x=2 hoặc x=1/5

c, <=> 5x.(x-3)-(x-3)=0

<=>(x-3).(5x-1)=0

<=> x-3=0 hoặc 5x-1 = 0

<=> x=3 hoặc x=1/5

k mk nha

217 x 45 + 50 x 217 + 217 x 5

= 217 x (45 + 50 + 5)

= 217 x 100

= 21 700

\(=217\left(-46-15-40+1\right)=217\left(-100\right)=-21700\)

217 . ( - 46 ) - ( - 217 ) . ( - 15 ) - 217 . 40 + 217

= 217 . ( - 46 - 15 - 40 + 1 )

= 217 . ( - 100 )

= - 21 700

806cm = 8,06m

806cm = 800cm + 6cm = 8m 6cm = 8 6 100  m=8,06m

75cm = 7,5dm

75cm = 70cm + 5cm = 7dm 5cm = 7 5 10  dm=7,5dm

24dm= 2,4m

24dm = 20dm + 4dm = 2m 4dm = 2 4 10  m=2,4m

423cm = 4,32m

432cm = 400cm + 32cm = 4m 32cm = 4 32 100  m=4,32m

217 + [43 + (–217) + (–23)]

= 217 + 43 + (–217) + (–23)

= [217 + (–217)] + [43 + (–23)]

= 0 + 20 = 20.

217 + [ 43 + (–217) +(–23)].

a/ (- 2010) - (119 - 2010)

= (- 2010) - 119 + 2010

= - 119

b/ 217 + [43 + (- 217) + (- 23)]

= 217 + [43 + (-217) - 23]

= 217 + (-217) + 20

= 20