Tim x
50 -2 x ( x +1 )=20
Tinh nhanh
147+230+53+70
7*85+27*7-7*12
58*75+58*50-58*25
Tinh nhanh
a ) 18*76+24*18-150
b ) 147 +230+53+70
c) 7*85+27*7-7*12
d) 58*75+58*50-58*25
e) 2 va3/5-2/5*(5/8-7/12)
f ) 1/3-5/4*4/15
1) Tinh nhanh:
a) 18*76+24*18-150
b) 147+230+53+70
c) 7*85+27*7-7*12
d) 58*75+58*50-58*25
e)2va3/5-2/5*(5/8-7/12)
f) 1/3-5/4*4/15
Avatar của mình là cách giải bài toán 109
1 . Tính nhanh
a/ 15 . ( 27 + 18 + 6 ) + 15 . ( 23 + 12 )
b/ 14 . 35 . 5 + 10 . 25 .7 + 20 . 70
c/ 53 . ( 51 + 4 ) + 53 . ( 49 + 96 ) + 53
d/ 46 . ( 27 + 75 ) + 8 . ( 58 + 25 ) . 2
a) 15 . (27 + 18 + 6 ) + 15 . ( 23 +12 ) = 15. 51 + 15 . 35 = 765 + 525 = 1290
b) 14 . 35 . 5 + 10 . 25 . 7 + 20 . 70 = 2450 + 1750 + 1400 = 2452450
c) 53 . ( 51 + 4 ) + 53 . ( 49 + 96 ) + 53 = 53 . 55 + 53 . 145 + 53 = 2915 . 7685 = 22401775
d) 46 . ( 27 +75 ) +8 . ( 58 + 25 ) + 8 . ( 58 + 25 ) . 2 = 46 . 102 + 8 . 83 + 8 . 83 = 4692 + 664 + 664 = 6020
1) 58× 75+ 58× 50 -58 × 25
2) 2và 3/5 - 3/5 × ( 5/8- 7/12)
3) 1/3 - 5/4 × 4/15
1) 58× 75+ 58× 50 -58 × 25
= 58( 75 + 50 - 25 )
= 58 . 100
= 5800
1/ 58 x 75 + 58 x 50 - 58 x 25
= 58 x ( 75 + 50 - 25 )
= 58 x 100
= 5800
2/= \(2\frac{3}{5}-\frac{3}{5}\cdot\frac{11}{84}\)
\(=\frac{13}{5}-\frac{3}{5}\cdot\frac{11}{84}\)
\(=\frac{13}{5}-\frac{11}{140}\)
\(=\frac{364-11}{140}\)
\(=\frac{353}{140}\)
3/ \(\frac{1}{3}-\frac{5}{4}\cdot\frac{4}{15}\)
\(=\frac{1}{3}-\frac{1}{3}\)
\(=0\)
a, 35 x 34 + 35 x 38 + 65 x 75 + 45 x 65
b, 39 x 8 + 60 x 2 + 21 x 8
c, 58 x 75 + 58 x 50 - 58 + 25
d, 125 x 98 - 125 x 46 - 52 x 25
a.35 x 34 + 35 x 38 + 65 x 75 + 45 x 65
= 35 x (34 + 38) + 65 x 75 + 65 x 45
= 35 x 72 + 65 x (75+45)
= 35 x 72 + 65 x 120
= 35 x 72 + 65 x (72 + 48)
= 35 x 72 + 65 x 72 + 65 x 48
= (35+65) x 72 + 65 x 48
= 100 x 72 + 65 x 48
= 7200 + 3120
= 10320
b.39 x 8 + 60 x 2 + 21 x 8
=39 x 8 + 15 x 4 x 2 +21 x 8
= 39 x 8 + 15 x 8 + 21 x 8
=(39 + 15 + 21) x 8
= 75 x 8
= 600
c.58 x 75 + 58 x 50 - 58 + 25
= 58 x 75 + 58 x 50 - 58 x 1 + 25
= 58 x(75+50-1)+25
= 58 x 124 + 25
= 7192 + 25
= 7217
d.125 x 98 - 125 x 46 - 52 x 25
= 25 x 5 x 98 - 25 x 5 x 46 - 25 x 52
= 25 x 490 - 25 x 230 - 25 x 52
= 25 x (490 - 230 - 52)
= 25 x 208
= 5200
1)Thuc hien phep tinh(nhanh neu co the):
a)53-2÷100÷4+23×5
b)295-(31-22×5)2
c)58×75+58×50-28:25
d)[(-15)+(-21)]+(25-40)
2)Tim x, biet:
a)156-(x+61)=82
b)6x-302=23×5
c)x-[42+(-28)]=8
d)|x-3|=|5|+|-7|
♥
Cac ban giai nhanh hai bai nay ho minh nhe!♥
2 . 53 . 27 + 6 . 9 . 87 - 3 . 18 . 40 = ???
12 . 25 + 29 . 25 + 59 . 25 = ???
43 . 37 + 93 . 43 + 57 . 61 + 69 . 57 = ???
12 . 53 + 53 . 172 - 53 = ???
35 . 54 + 35 . 58 + 65 . 75 + 65 . 45 = ???
39 . 8 + 70 . 3 + 31 . 8 = ???
2 . 53 . 27 + 6 . 9 . 87 - 3 . 18 . 40
= 2. 53 . 9 . 3 + 2. 3 .9 .87 - 3 .2 .9 .40
= 54.53+54.87-54.40
=54(53+87-40)
=54. 100=5400
12 . 25 + 29 . 25 + 59 . 25
= 25 . ( 12+29+59)
=25 . 90
=2250
43 . 37 + 93 . 43 + 57 . 61 + 69 . 57
= 43.(37+93)+57(61+69)
=43.130+57.130
=130.(43+57)
=130.100
=13 000
12 . 53 + 53 . 172 - 53
=53(12+172-1)
=53.184
=9752
35 . 54 + 35 . 58 + 65 . 75 + 65 . 45
=35(54+58)+65(75+45)
=35.112+65.120
=3920+7800
=11720
39 . 8 + 70 . 3 + 31 . 8
=8(39+31)+70.3
=8.70+70.3
=70.(8+3)
=70.11
=770
2 . 53 . 27 + 6 . 9 . 87 - 3 . 18 . 40
= ( 2 . 27 ) . 53 + ( 6 . 9 ) . 87 - ( 3 . 18 ) . 40
= 54 . 53 + 54 . 87 - 54 . 40
= 54(53+87-40)
= 5400
12 . 25 + 29 . 25 + 59 . 25
= 25( 12 + 29 + 59 )
= 2500
43 . 37 + 93 . 43 + 57 . 61 + 69 . 57
= 43( 37 + 93 ) + 57(61 + 69 )
= 5590 + 7410
= 13000
12 . 53 + 53 . 172 - 53
= 53( 12 + 172 ) - 53
= 9752 - 53
= 9699
35 . 54 + 35 . 58 + 65 . 75 + 65 . 45
= 35( 54 + 58 ) + 65( 75 + 45 )
= 3920 + 7800
= 11720
a.58 . 75 + 58 . 50 - 58 . 25
b.20 : 22 - 59 : 58
c. ( 519 : 517- 4 ) : 7
a/ \(58.75+58.50-58.25\)
\(=58\left(75+50-25\right)\)
\(=58.100\)
\(=5800\)
b/ \(20\div2^2-5^9\div5^8\)
\(=20\div4-5\)
\(=5-5\)
\(=0\)
c/ \(\left(5^{19}\div5^{17}-4\right)\div7\)
\(=\left(5^2-4\right)\div7\)
\(=\left(25-4\right)\div7\)
\(=21\div7\)
\(=3\)
Tình nhanh
a) 18x 76 +24x -150
b) 147+230+53+70
c) 7x 85+27 x 7-7 x 12
D) 2va3/5 -2/5x( 5/8-7/12)