Question

BT. GCPT sau :

a) 7x + 21 = 0

b) 5x - 2 = 0

c) 12 - 6x =0 

d) -2x + 14 = 0

             Giups mk vs . thank m.n 

 

 

Answer 1

a) 7x + 21 = 0 <=> 7x = -21 <=> x=-3

b) 5x - 2 = 0 <=> 5x =2 <=> x= 2/5

c) 12 - 6x =0 <=>6x = -12 <=> x= -2 

d) -2x + 14 = 0 <=> 2x = 14 <=> x = 7

 

Answer 2

a) 7x + 21 = 0

<=> 7x = -21

<=> x = -3

Vậy S = {-3}

b) 5x - 2 = 0

<=> 5x = 2

\(\Leftrightarrow x=\dfrac{2}{5}\)

Vậy:....

c) 12 - 6x =0 

<=> 6x = 12

<=> x = 2

Vậy S = {2}

d) -2x + 14 = 0

<=> -2x = -14

<=> x = 7

Vậy S = {7}