Chị xinh quá 

3,9 haaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

Vì \(A=\overline{2009abc}⋮315\)

nên c=0 hoặc c=5

TH1: c=0

=>(a,b)=(0;7) hoặc (a,b)=(7;0) để A chia hết cho 9

TH2: c=5

=>(a,b)=(3;8) để A chia hết cho 9

\(\left(a,b,c\right)\in\left\{\left(0;7;0\right);\left(3;8;5\right);\left(7;0;0\right)\right\}\)

 x chia hết cho 35 , x chia hết cho 63 , x chia hết 105 nên x thuộc BC(35;63;105)

Ta có:

63=3^2x7

35=5x7

105=3x5x7

=>BCNN(35;63;105)=3^3x5x7=315

=>x  thuộc B(315)

B(315)={0;315;630;945;...}

Mà  315 < x < 632 nên x=630

cảm ơn Trần Thùy Dung nha 

đc 1 lân thôi bn 

a=.8

b=8

c=5

à bài này dễ ấy mà :v

Bài 1:

a, \(92.4-27=\left(x+350\right):x+315\)

\(\Rightarrow\left(x+350\right).\dfrac{1}{x}=92.4-27-315\)

\(\Rightarrow1+\dfrac{350}{x}=26\)

\(\Rightarrow350:x=25\Rightarrow x=14\)

b, \(720:\left[41-\left(2x+5\right)\right]=2^3.5\)

\(\Rightarrow720:\left(41-2x-5\right)=8.5\)

\(\Rightarrow720:\left(36-2x\right)=40\)

\(\Rightarrow36-2x=18\Rightarrow2x=18\Rightarrow x=9\)

Chúc bạn học tốt!!!

1)

a)

\(92.4-27=(x+350):x+315\)

\(368-27=(x+350):x+315\)

\(341=(x+350):x+315\)

\((x+350):x=341-315=26\)

\(26x=x+350\)

\(25x=350\)

\(x=14\)

b)

\(720:[41-(2x+5)]=2^3.5\)

\(720:[41-(2x+5)]=40\)

\(41-(2x+5)=18\)

\(2x+5=23\)

\(2x=18\)

\(x=9\)