Merry Christmas

a + 1 là bội của a - 1

=> a + 1 chia hết cho a - 1

=> [(a - 1) + 2] chia hết cho a - 1

=> 2 chia hết cho a - 1, a - 1 thuộc ước của 2 = {1; 2}

a - 1 = 1

=> a = 2

a - 1 = 2

=> a = 3

Vậy a thuộc {2; 3}

(=) 5^2x-3 -2 =3 

(=) 5^2x-3 = 5

(=)2x-3=1

(=)2x=4

(=)x=2

#Học-tốt

a)trên tia Ox có ON <OM (7cm<15cm)

nên điểm n nằm giữa O,M (1)

b)từ (1) suy ra :

         ON+NM=OM ( ON=7cm,Om=15cm)

hay 7+MN=15

          MN=15-7

         MN=8cm 

c)trên tia Ox có MI < MN (1cm<8cm)

nên I nằm giữa 2 điểm M,N (2)

nên: NI+IN=NM

hay NI+1=8

          NI=8-1

         NI=7cm

mà ON=7cm

suy ra ON=NI(=7cm)  (3)

từ (1) (2) cho ta :
N nằm giữa 2 điểm O,I (4)

từ (3) (4) ta đc

N là trung điểm của OI

chịuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu

bằng 0

ko bt và ko CARE

chịuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu

câu d AC và CA

học tốt

D

#Học-tốt

| x - 6 | = 89

ta có 2 trường hợp

th1

x -6  = 89

x  =  89 + 6

x = 95

th2

x -6 = -89

x     = (-89) + 6

x     = -82

=> x = 95;-82

giáng sinh vv

thank bạn nha

bài này dễ mà

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