x + 120 = 452 + 100
x + 120 = 452 + 100
x+120=552
x=552-120
x=432 nha bạn.
Nhớ k cho mình nha
x + 120 = 452 + 100
x + 120 = 552
x = 552 - 120
x = 432
452 x 17 + 452 x 98 - 452 x 15 tính thuận tiện
\(452\times17+452\times98-452\times15\)
\(\Rightarrow452\times\left(17+98-15\right)\)
\(\Rightarrow452\times100\)
\(\Rightarrow45200\)
120 x 100 + 120 * 100 - 120 * 100
120 x 100 + 120 x 100 - 120 x 100
= (120 x 100) + (120 x 100) - (120 x 100)
= 12000 + 12000 - 12000
= 24000 - 12000
= 12000
Bài 1 : Tính giá trị của biểu thức
a ) 279 452 - 452 x 459 b ) 5076 : 47 x 108
a ) 279 452 - 452 x 459
= 279452 - 207468
= 71984
b ) 5076 : 47 x 108
= 108 x 108
= 11664
A) 279 x 452-452 x 459
=452 x (279-459)
=452 x (-200)
=-90400
B)5076:47 x 108
=108 x 108
=11664
= 279452 - 207468
= 71984
= 108 x 108
= 11664
452 : 10 ............ 452 x 0,01
Dấu thích hợp cần điền vào chỗ chấm là:
A. < B. > C. =
Tính bằng hai cách theo mẫu:
Mẫu: 452 × 39 = 452 × (30 + 9)
= 452 × 30 + 452 × 9
= 13560 + 4068 = 17628
452 × 39 = 452 × (40 – 1 )
= 452 × 40 + 452 × 1
= 18080 - 452 = 17628
a) 896 × 23
b) 547 × 38
a) 896 × 23 = 896 × (20 + 3)
= 896 × 20 + 896 × 3
= 17920 + 2688
= 20608
896 × 23 = 896 × (24 – 1 )
= 896 × 24 – 896 × 1
= 211504 – 896
= 20608
b) 547 × 38 = 547 × (30 + 8)
= 547 × 30 + 547 × 8
= 20786
547 × 38 = 547 × (39 – 1)
= 547 × 39 - 547 × 1
= 21333 – 547
= 20786
120 : 30 x 100 + 1000 - 100 = ?
120 : 30 x 100 + 1000 - 100 =?
= 4 x 100 + 1000 - 100
= 400 + 1000 - 100
= 1400 - 100
= 1300
120 : 30 x 100 + 1000 - 100
= 4 x 100 + 1000 - 100
= 400 + 1000 - 100
= 1400 - 100
= 1300
=4x100+1000-100
=400+1000-100
=1400-100
=1300
Tính nhẩm:
a) 27 × 10 = …...; 72 × 100 =…...; 14 × 1000 =…...
86 × 10 = …...; 103 × 10 =…...; 452 × 1000 =…...
358 × 10 = …...; 1977 × 100 =…...; 300 × 1000 =…...
b) 80 : 10 = …...; 400 : 100 =…... ;6000 : 1000 =…...
300 : 10 = …...; 4000 : 100 =…... ;60000 : 1000 =…...
2000 : 10 =…...; 40000 : 100 =…... ;600000 : 1000 =…...
c) 64 × 10 =…...; 32 × 100 =…...; 95 × 1000 =…...
640 : 10 =…...; 3200 : 100 =…...; 95000 : 1000 =…...
a) 27 × 10 = 270; 72 × 100 = 7200; 14 × 1000 = 14000
86 × 10 = 860; 103 × 10 = 10300; 452 × 1000 = 452000
358 × 10 = 3580; 1977 × 100 = 197700; 300 × 1000 = 300000
b) 80 :10 = 8; 400 : 100 = 4 ;6000 : 1000 = 6
300 : 10 = 30; 4000 : 100 = 40 ; 60000 : 1000 = 60
2000 :10 = 200; 40000 :100 = 400 ;600000 : 1000 = 600
c) 64 × 10 = 640; 32 × 100 = 3200; 95 × 1000 = 95000
640 : 10 = 64; 3200 : 100 = 32; 95000 : 1000 = 95
Tìm x :
120 + 80 = 500 - x
100 + 100 = 400 - x
\(120\)\(+\)\(80\)\(=\)\(500\)\(-\)\(x\) \(100\)\(+\)\(100\)\(=\)\(400\)\(-\)\(x\)
\(200\) \(=\)\(500\)\(-\)\(x\) \(200\) \(=\)\(400\)\(-\)\(x\)
\(500\)\(-\)\(200\)\(=\)\(x\) \(400\)\(-\)\(200\)\(=\) \(x\)
\(300\) \(=\) \(x\) \(200\) \(=\) \(x\)
120 + 80 = 500 - x
200 = 500 - x
x = 300
100 + 100 = 400 - x
200 = 400 - x
x = 200
120 + 80 = 500 - x
100 + 100 = 400 - x
Ta có :
120 + 80 = 500 - x
=> 500 - x = 200
=> x = 300
Lại có :
100+100=400-x
=> 400-x = 200
=> x = 200