Sửa đề: 36*117-36*43-72*30

=36(117-43-60)

=36*14=504

Hướng dẫn giải:

36 x 43 = 1548

123 x 25 = 3075

245 x 34 = 8330

8188:215

43 x 36 + 57 x 90 + 43 x 84 +57 x30

=[43 x (36+84)] + [57 x (90+30)]

=43 x 120 + 57 x 120

=(43+57) x 120

=100 x 120

=12000

43 x 36 + 57 x 90 + 43 x 84 +57 x 30

= 43 x 36 + 43 x 84 + 57 x 90 + 57 x 30

= [43 x (36 x 84)] + [57 x (90 + 30)]

= 42 x 120 + 57 x 120

= (42 + 57) x 120

=> 100 x 120

=> 12000

          Đáp số: 12000

9700 : 100 + 36 x 12 = 529

(160 x 5 - 25 x 4) : 4= 175

108 x (23 + 7) = 3240

215 x 86 + 215 x 14 = 21500

3 x 128 - 43 x 128= -5120

529

175

3240

21500

-5120 (lớp 4 học âm hẻ)

câu a thì lấy 15400:25 là được.

a) \(15400:x=25\)

\(\Rightarrow x=15400:25\)

\(\Rightarrow x=616\)

b) \(\left(x+3\right):247=675:135\)

\(\Rightarrow\left(x+3\right):247=5\)

\(\Rightarrow x+3=5\times247\)

\(\Rightarrow x+3=1235\)

\(\Rightarrow x=1235-3\)

\(\Rightarrow x=1232\)

c) \(1224:\left(x-8\right)=24\)

\(\Rightarrow\left(x-8\right)=1224:24\)

\(\Rightarrow x-8=51\)

\(\Rightarrow x=51+8\)

\(\Rightarrow x=59\)

a) 36 x 25 x 4 = 36 x ( 25 x 4) = 36 x 100 = 3600

18 x 24 : 9= 24 x ( 18:9) = 24 x 2 = 48

41 x 2 x 8 x 5= 41 x 8 x ( 5x2) = 41 x 8 x 10 = 3280

b) 108 x (23 + 7)= 108 x 30 = 3240 

215 x 86 + 215 x 14 = 215 x ( 86 + 14) = 215 x 100 = 21500 

53 x 128 – 43 x 128= 128 x ( 53 - 43) = 128 x 10 = 1280

\(a,35\times25\times4=36\times100=3600\)

\(18\times24:9=18:9\times24=2\times24=48\)

\(41\times2\times8\times5=\left(2\times5\right)\times\left(41\times8\right)=10\times328=3280\)

\(b,108\times\left(23+7\right)=108\times30=3240\)

\(215\times86+215\times14=215\times\left(86+14\right)=215\times100=21500\)

\(53\times128-43\times128=128\times\left(53-43\right)=128\times10=1280\)

gọi biểu thức là s

ta có:

s = {12345 x (45 + 54 +1)} + {(216+1224+960) : 24}

s= (12345 x 100) + (2400 : 24 )

s = 1234500 + 100

s= 1234600