x + 50 = 25 x 4
4 x 125 x 25 x 8
2 x 8 x 50 x 25 x 125
2 x 3 x 4 x 5 x 50 x 25
25 x 20 x 125 x 8 - 8 x 20 x 5 x 125
x + 25 x 4 = 50 x 50 x 100
x + 25 x 4 = 50 x 50 x 100
x + 25 x 4 = 250000
x + 25 = 250000 : 4
x + 25 = 62500
x = 62500 - 25
x = 62475
x + 25 x 4 = 50 x 50 x 100
x + 25 x 4 = 250000
x + 25 = 250000 : 4
x + 25 = 62500
x = 62500 - 25
x = 62475
\(x+25.4=50.50.100\)
\(x+25.4=250000\)
\(x+100=250000\)
\(x=250000-100\)
\(x=249900\)
Tính bằng cách thuận tiện nhất:
a) 71 x 5 x 4 = ………………… = ………………… = …………………
b) 123 x 50 x 2 = ………………… = ………………… = …………………
c) 4 x 138 x 25 = ………………… = ………………… = …………………
d) 25 x 96 x 4 = ………………… = ………………… = …………………
e) 5 x 81 x 2 = ………………… = ………………… = …………………
g) 50 x 104 x 2 = ………………… = ………………… = …………………
Hướng dẫn giải:
a) 71 x 5 x 4 = 71 x (5 x 4) = 71 x 20 = 1420
b) 123 x 50 x 2 = 123 x (50 x 2) = 123 x 100 = 12300
c) 4 x 138 x 25 = (4 x 25) x 138 = 100 x 138 = 13800
d) 25 x 96 x 4 = (25 x 4) x 96 = 100 x 96 = 9600
e) 5 x 81 x 2 = (5 x 2) x 81 = 10 x 81 = 810
g) 50 x 104 x 2 = (50 x 2) x 104 = 100 x 104 = 10400
tinh nhanh
4 x 125 x 25 x 8
2 x 8 x 50 x25 x125
2 x 3 x 4 x 5 x 50 x 25
25 x 20 x 125 x 8 - 8 x 20 x 5 x 125
4 × 125 × 25 × 8
= (4 × 25) × (125 × 8)
= 100 × 1000
= 100 000
2 × 8 × 50 × 25 × 125
= (2 × 50) × (8 × 125) × 25
= 100 × 1000 × 125
= 12 500 000
2 × 3 × 4 × 5 × 50 × 25
= (2 × 50) × (4 × 25) × (3 × 5)
= 100 × 100 × 15
= 150 000
25 × 20 × 125 × 8 - 8 × 20 × 5 × 125
= 8 × 125 × 20 × (25 - 5)
= 1000 × 20 × 20
= 400 000
- (25 x 4) x (125 x8)=100 x 1000 =100000
- (50 x 2) x (8 x 125) x 25=100 x 1000 x 25 =2500000
- (2 x 50 ) x (4 x 25) x (3 x5)=100 x 100 x 15=150000
- 25 x 20 x125 x 8 - 5
= (20 x 5) x (125 x 8) -25=100 x 1000 -5 =100000 - 5 =99995
4 *125*25*8
=4*25*125*8
=100*1000
=100000
2*8*50*25*125
=2*50*8*125*25
=100*1000*25
=2500000
2*3*4*5*50*25
=2*50*4*25*3*5
=100*100*15
=150000
25*20*125*8-8*20*5*125
=25*4*5*125*8-8*125*20*5
=100*1000*5-1000*100
=500000-100000
=400000
=
bài 1:
4 x 125 x 25 x 8 = 2 x 8 x 50 x 25 x 125 =
2 x 3 x 4 x 5 x 50 x 25 = 25 x 20 x 125 x 8 - 8 x 20 x 5 x 125 =
\(4.125.25.8\)
\(=\left(4.25\right).\left(125.8\right)\)
\(=100.1000\)
\(=100000\)
\(2.3.4.5.50.25\)
\(=\left(2.50\right).\left(4.25\right).\left(3.4.5\right)\)
\(=100.100.60\)
\(=10000.60\)
\(=600000\)
\(2.8.50.25.125\)
\(=\left(2.50\right).\left(8.125\right).25\)
\(=100.1000.25\)
\(=100000.25\)
\(=2500000\)
2 x 4 x 6 x 8 x 50 x 25 x 125
2 x 4 x 6 x 8 x 50 x 25 x 125
= (2 x 50 ) x ( 4 x 25 ) x ( 125 x 8 ) x 6
= 100 x 100 x 1000 x 6
= 60000000
a) 25 x 5 x 13 x 4
87 x 125 x 8 x 4
b) 50 x 76 x 2
19 x 4 x 25 x 8
c) 303 x 20 x 6 x5
4 x 889 x 25
a, 25*5*13*4=6500
87*125*8*4=348000
b,50*76*2=7600
19*4*25*8=15200
c,303*20*6*5=181800
4*889*25=88900
a)6500,348000.
b)7600,15200.
c)181800,88900.
a,= ( 25x4 ) x ( 13x5 )
= 100 x 65
= 6500
= ( 125x8 ) x ( 87x4 )
= 1000 x 348
= 348000
b, = ( 50x2 ) x 76
= 100 x 76
= 7600
= ( 4x25 ) x ( 19x8 )
=100 x 152
= 15200
c, = ( 20x5 ) x ( 303x6 )
= 100 x 1818
= 181800
= ( 4x25 ) x 889
= 100 x 889
= 88900
3/4+x+x-50%x=-25
Tính bằng cách thận tiện:
2 x 25 x 50 x 4
=
=
2 x 25 x 50 x 4
= ( 2 x 50 ) x ( 25 x 4 )
= 100 x 100
= 10000
2 . 25 . 50 . 4 = ( 2 . 50 ) . ( 25 . 4 ) = 100 . 100 = 10 000
Tính nhanh:
a]2 x 3 x 4 x 8 x 50 x 25 x 125