125/100 = x/45
tính nhanh A | 38 + 125 + 29 +17
B | 312 X 45 : 15
C | 100 - 99+ 98 - 97 + 96 - 95 + 94 - 93 + 92 -91
D |(125 x 36 ) : ( 5 x 9 )
A=[(38+17)+125]+29
A=175+29
A=204
B=312.3
B=936
C=1+1+1+1+1
C=5
D=(125:5).(36:9)
D=25.4
D=100
tính hợp lí
a) 135 x (-27) + 27 x 235
b) 36 x (-125) - 125 x (-46)
c) 32 x (-64) - 64 x 68
d) (145 - 45) x (-31) + 31 x (-100)
a) 135 . (-27) + 27 . 235
= 27 . (235 - 135)
= 27 . 100
= 2700
b) 36 . (-125) - 125 . (-46)
= 125 . (-36 + 46)
= 125 . 10
= 1250
c) 32 . (-64) - 64 . 68
= 64.(-32 - 68)
= 64.(-100)
= -6400
d) (145 - 45) . (-31) + 31 . (-100)
= 100 . (-31) + 31.(-100)
= 100.(-31 - 31)
= 100.(-62)
= -6200
a)
=(-135)x27+27x235
=27x[+(235+135)]
=27x31725
=856575
b)
=(-36)x125-125x(-46)
=125x[-(36+46)]
=125x(-1656)
=-207000
c)
=(-32)x64-64x68
=64x[-(68-32)]
=64x(-36)
=-(64x36)
=-2304
d)
=100x(-31)+31x(-100)
=(-100)x31+31x(-100)
=31x[-(100+100)]
=31x(-200)
=-(31x200)
=-6200
chúc học tốt nhớ tích cho tui nha
nếu tui đúng chứ tui cũng hông có chắc nữa
1 : Tính nhanh:
a, 2376 + 3425 - 376 - 425
b, 4638 - 2437 + 5362 - 7563
c, 45 + 45 + 45 + 45 + 15 + 15 + 15 + 15
d, 4 x 125 x 25 x 8
e, 2 x 8 x 50 x 25 x 125
2 : Tính nhanh bằng hai cách:
125 + 125 + 125 + 125 - 25 - 25 - 25 - 25
1 : Tính nhanh:
a) 2376 + 3425 - 376 - 425 = ( 2376 - 376 ) + ( 3425 - 425 )
= 2000 + 3000
= 5000
b)4638 - 2437 + 5362 - 7563 = 2210 + ( - 2210 )
= 0
c) 45 + 45 + 45 + 45 + 15 + 15 + 15 + 15
= 45 x 4 + 15 x 4
= ( 45 + 15 ) x 4
= 60 x 4
= 240
d) 4 x 125 x 25 x 8 = ( 4 x 25 ) x ( 125 x 8 )
= 100 x 1000
= 100000
e) 2 x 8 x 50 x 25 x 125 = ( 2 x 50 ) x ( 8 x 125 ) x 25
= 100 x 1000 x 25
= 100000 x 25
= 2500000
2 : Tính nhanh bằng 2 cách:
C1 : 125 + 125 + 125 + 125 - 25 - 25 - 25 - 25
= ( 125 - 25 ) + ( 125 - 25) + ( 125 - 25 ) + ( 125 - 25 )
=100 + 100 + 100 + 100
= 100 x 4
= 400
C2 : 125 + 125 + 125 + 125 - 25 - 25 - 25 - 25
= 125 x 4 - 25 x 4
= ( 125 - 25 ) x 4
= 100 x 4
= 400
1: Tính nhanh:
a, 2376 + 3425 - 376 - 425
= ( 2376 - 376 ) + ( 3425 - 425 )
= 2000 + 3000
= 5000.
b, 4638 - 2437 + 5362 - 7563
= 2210 + (-2210)
= 0.
c, 45 + 45 + 45 + 45 + 15 + 15 + 15 + 15 + 15
= ( 45 + 15 ) + ( 45 + 15 ) + ( 45 + 15 ) + ( 45 + 15 )
= 60 + 60 + 60 + 60
= 240.
d, 4 x 125 x 25 x 8
= ( 4 x 25 ) x ( 125 x 8 )
= 100 x 1000
= 100000.
e, 2 x 8 x 50 x 25 x 125
= ( 2 x 50 ) x ( 8 x 125 ) x 25
= 100 x 1000 x 25
= 2500000.
2: Tính nhanh bằng hai cách:
125 + 125 + 125 + 125 - 25 - 25 - 25- 25
= ( 125 - 25 ) + ( 125 - 25 ) + ( 125 - 25 ) + ( 125 -25 )
= 100 + 100 + 100 + 100
= 400.
Tính nhanh
a,125 *45 +45 *25 *90 *25
b.303 *85 -85 -103 -58 *100
c.25 * 20 * 4 - 100 *40
d.175 -26 +25 - 74 +125 * 1,6 * 80
Nhớ trình ra
45 /{390/[5*100-(125 +49+5)]}
\(45:\left\{390:\left[5.100-\left(125+49+5\right)\right]\right\}\)
\(=45:\left\{390:\left[500-179\right]\right\}\)
\(=45:\left\{390:321\right\}\)
\(=45:\dfrac{130}{107}\)
\(=\dfrac{963}{26}\)
tính nhanh
a.125 *45 +45 *25 +90 *25
b. 303 *85 -85 -103 -85 *100
c.25 *20 *4 -200 *40
d. 175 - 26 + 25 - 125 * 1,6 *80
a) 125 x 45 + 45 x 25 + 90 x 25
=125 x 45 + 45 x 25 + 2 x 45 x 25
=45 x [125 + 25 + ( 2 x 25 )]
=45 x [125 + 25 + 50]
=45 x 200
= 9000
c) 25 x 20 x 4 - 200 x 40
=25 x 2 x 10 x 4 - 200 x 40
=(25 x 2 x 4) x 10 - 200 x 40
=200 x 10 - 200 x 40
=200 x (10 - 40)
=200 x (-30)
= -6000
1) Tìm x :
x + 125 - 45 + ( 12 + 23 ) = 155
x * 12 = ( 45 + 45 )
a) x + 125 - 45 + (12+23) = 40
=> x + 125 - 45 + 35 = 40
=> x + 115 = 40
=> x = 40 - 115
=> x = -75
b) x * 12 = (45 + 45)
=> x * 12 = 90
=> x = 90 : 12
=> x = 7,5
x + 125 - 45 + ( 12 + 23 ) = 40
=> x + 125 +( -45) + 35 = 40
=> x + 80 +35 = 40
=> x + 115 = 40
=> x = -75
x * 12 = ( 45 + 45 )
=> x * 12 = 90
=> x = 90 : 12
=> x = 15/2 = 7.5
a) x + 125 - 45 + (12 + 23) = 40
x + 125 - 45 + 35 = 40
x = 40 - 35 + 45 - 125
x = - 65
b) x * 12 = 45 + 45
x * 12 = 90
x = 90 : 12
x = 7,5
45 :x bằng 125
\(4^5:x=125\)
\(x=4^5:125\)
\(x=1024:125\)
\(x=8,192\)
Vậy \(x=8,192\)
1) Tính nhanh:
a, 125 x 3 + 125 x 125 x 6
b, ( 245 x 99 + 245 ) - ( 145 x 101 - 145 )
c, 154 x ( 28 + 52 ) - 45 x ( 26 + 54 )
a) 125.3+125.125.6
=125.3+125.750
=125.(3+750)
=125.753
=94125
b) (245.99+245)-(145.101-145)
=(245.(99+1))-(145.(101-1))
=245.100-145.100
=(245-145).100
=100.100
=10000
c) 154.(28+52)-45.(26+54)
=154.80-45.80
=(154-45).80
=109.80
=8720
a) 125x3+125+125x6
=125x(3+1+6)
=125x10
=1250
b) (245x99+245)-(145x101-145)
=(245x99+245)-(145x100)
=(245x100)-14500
=24500-14500
10000
c) 154x80-45x80
=80x(145-45)
=80x100
=8000
a, 125 x 3 + 125 x 125 x 6
=125 x 3 + 125 x 750
=125 x( 3+750)
=125 x753
=94125
b, ( 245 x 99 + 245 ) - ( 145 x 101 - 145 )
=[245 x ( 99+1 )] - [145 x ( 101-1 )]
=( 245 x 100 ) - ( 145 x 100 )
=24500 - 14500
=10 000
c, 154 x ( 28 + 52 ) - 45 x ( 26 + 54 )
=154 x 80 - 45 x 80
=(154-45)x80
=109 x80
=8720