5,62 : 10 = 0,562

0,95 : 100 = 0,0095

1342,6 : 1000 = 1,3426

245 x 0,01 = 2,45

356 x 0,1 = 35,6

23,45 x 100 = 2345

384,90 x 100 = 38490

4,89 x 10 = 48,9 

= 356 . (445 - 245 )

= 356 . 200

= 71200

356(445-245)
= 356. 200
=71200

 

a.10+13+16+19+.......+97+100

=(10+100)+(13+97)+(16+94)+.....+(52+58)+55

=110+110+110+.......+110+55

=110x18+55

=1980+55

=2035

b.5+10+15+20+.......+95+100

=(100+5)+(10+95)+....+(55+50)

=105+105+...+105

=105x10

=1050

tim x,y biet:

c.135-y:4=106

y:4=135-106

y:4=29

y=29:4

y=\(\frac{29}{4}\)

d.356:y+241=245

256:y=245-241

356:y=4

y=356:4

y=89

\(356:y+241=245\\ \Rightarrow356:y=245-241\\ \Rightarrow356:y=4\\ \Rightarrow y=356:4\\ \Rightarrow y=89\)

y=89

356:y+241=245⇒356:y=245−241⇒356:y=4⇒y=356:4⇒y=89

giúp mik vs

\(a)245^2+490\cdot54+54^2-199^2\\=(245^2+2\cdot245\cdot54+54^2)-199^2\\=(245+54)^2-199^2\\=299^2-199^2\\=(299-199)(299+199)\\=100\cdot498\\=49800\\---\\b)356^2-356\cdot246+123^2-133^2\\=(356^2-2\cdot356\cdot123+123^2)-133^2\\=(356-123)^2-133^2\\=233^2-133^2\\=(233-133)(233+133)\\=100\cdot366\\=36600\)

\(---\)

\(c)468^2-412^2-110\cdot412-55^2\\=468^2-(412^2+110\cdot412+55^2)\\=468^2-(412^2+2\cdot412\cdot55+55^2)\\=468^2-(412+55)^2\\=468^2-467^2\\=(468-467)(468+467)\\=1\cdot935\\=935\\---\)

\(d)615^2+250\cdot615+125^2-540^2\\=(615^2+2\cdot615\cdot125+125^2)-540^2\\=(615+125)^2-540^2\\=740^2-540^2\\=(740-540)(740+540)\\=200\cdot1280\\=256000\)

#\(Toru\)

a,465

b,119

c,908

Chúc bạn học tốt

a) ( 525 + 245 ) - 305

= 770 - 305

= 465

b) 259 - ( 111 + 29 )

= 259 -140

= 119

c) ( 598 + 909 ) - ( 300 + 299 )

= 1507 - 599

= 908

Chúc bn hok tốt

a) ( 525 + 245 ) - 305 

     = 770 - 305 

     = 465.

b) 259 - ( 111 + 29 )

     = 259 - 140

     = 119.

c) ( 598 + 909 ) - ( 303 + 299 )

     = 1507 - 602

     = 905.

100 + 245 - 45 + 100 = 345 - 45 + 100 = 300 + 100 = 400

=400 nha bn

*** mk nha

100+245-45+100=400

Số cần tìm là:

245:100*100=245

Đáp số;245

Ai mình mình lại!

Giúp đỡ mình nha!

245

tk nha

245

tk nha