3/4+x+x-50%x=-25
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
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
=
25 . 15 + 75 . 45
-10 . 25 - 10 . 75 + 10 . 50
3^x-2 - 2^3 = 19
(2 x - 5)^3 = - 64
2(x-1)^2 + 3 = 35
125 - 25 (x + 3) = 50
2(x+ 3) - 1x = 4
a: =25(15+45*3)
=25*150
=3750
b: \(=-10\left(25+75-50\right)=-10\cdot50=-500\)
c: =>3^x-2=27
=>x-2=3
=>x=5
d: =>2x-5=-4
=>2x=1
=>x=1/2
e: =>2(x-1)^2=32
=>(x-1)^2=16
=>x-1=4 hoặc x-1=-4
=>x=-3 hoặc x=5
f: =>25(x+3)=75
=>x+3=3
=>x=0
Tính nhanh:
a]2 x 3 x 4 x 8 x 50 x 25 x 125
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 =
\(4.125.25.8\)
\(=\left(4.25\right).\left(125.8\right)\)
\(=100.1000\)
\(=100000\)
\(2.3.4.5.50.25\)
\(=\left(2.50\right).\left(4.25\right).\left(3.4.5\right)\)
\(=100.100.60\)
\(=10000.60\)
\(=600000\)
\(2.8.50.25.125\)
\(=\left(2.50\right).\left(8.125\right).25\)
\(=100.1000.25\)
\(=100000.25\)
\(=2500000\)
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
1/3 - x =5/6 -1/4
1/10 - {x - 3/25}=1/50
a) \(x=\dfrac{1}{3}-\dfrac{5}{6}+\dfrac{1}{4}=\dfrac{4}{12}-\dfrac{10}{12}+\dfrac{3}{12}=-\dfrac{3}{12}=-\dfrac{1}{4}\)
b) \(x-\dfrac{3}{25}=\dfrac{1}{10}-\dfrac{1}{50}=\dfrac{5}{50}-\dfrac{1}{50}=\dfrac{4}{50}=\dfrac{2}{25}\)
\(x=\dfrac{2}{25}+\dfrac{3}{25}=\dfrac{5}{25}=\dfrac{1}{5}\)
1/3 - x = 5/6 -1/4
1/3 - x = 7/12
x= 1/3 - 7/12
x -1/4
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
\(x+25.4=50.50.100\)
\(x+25.4=250000\)
\(x+100=250000\)
\(x=250000-100\)
\(x=249900\)
bài 2 viết mỗi tích, thương sau dưới dạng luỹ thừa
a) 4^10 x 2^30 b) 9^25 x 27^4 x 81^3 c) 25^50 x 125^5 d) 64^3 x 4^8 x 16^4
e)3^8:3^6 ; 2^10:8^3 ; 12^7 :6^7 ; 31^5 ; 81^3
f) 5^8 : 25^2 ; 4^9:64^2 ; 2^25 : 32^4 ; 125^3 : 25^4
a, 410. 230=220.230=250
b,925.274.813= 350.312.312=374
Tương tự các câu khác....
a, 410.230 = (22)10.230 = 220.230 = 250
b, 925.274.813 = (32)25.(33)4.(34)3 = 350.312.312 = 374
c, 2550.1255 = (52)50.(53)5 = 5100.515 = 5115
d, 643.48.164 = (26)3.(22)8.(24)4 = 218.216.216 = 250
e, 38 : 36 = 32
210 : 83 = 210 : (23)3 = 210 : 29 = 2
127 : 67 = (12 : 6)7 = 27
@Dương Tuyết Mai