Tính ( - 7 ) 20 : ( - 7 ) 18
A. 49
B. –49
C. – 14
D. 14
4×7/9×23
2×21/14×15
2×5×13/26×35
9×6-9×3/18
17×5-17/3-20
49+7×49/49
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. Tính
A, (49 mũ 5 * 7 mũ 16) : (7 mũ 18 * 7 mũ 6)=
B, (4 mũ 16 * 8 mũ 20) : (2 mũ 14 * 32 mũ 15)=
Kèm theo lời giải
a) (495 . 716) : (718.76)
=((72)5.716) :724
=(710.716) :724
=726 : 724=72=49
b) (416.820 ) : (214.3215)
=((22)16.(23)20) : (214.(25)15
=(232.260) : (214.275)
=292 : 289=23=8
1,Tính nhanh
a, 568 + 568 x 135 - 568 x 36
b, 17 x 49 + 49 x 37 + 54 x 26 + 54 x 25
c, 14 x 35 x 5 + 10 x 25 x 7 + 20 x 70
a, 568 + 568 x 135 - 568 x 36
= 568 x ( 1 + 135 - 36)
= 568 x 100
56 800
b, 17 x 49 + 49 x 37 + 54 x 26 + 54 x 25
= 49 x ( 17 + 37) + 54 x ( 26 + 25 )
= 49 x 54 + 54 x 51
= 54 x ( 49 + 51)
= 54 x 100
= 5 400
c, 14 x 35 x 5 + 10 x 25 x 7 + 20 x 70
= ( 2 x 35) x ( 7 x 5) + ( 10 x 7) x 25 + 20 x 70
= 70 x 35 + 70 x 25 + 20 x 70
= 70 x ( 35 + 25 + 20)
= 70 x 80
= 5 600
a) 568 + 568 x 135 - 568 x 36
= 568 x ( 1+1+135-1-36 )
=568 x 100
=5680
b) 17 x 49 + 49 x 37 + 54 x 26 + 54 x 25
= 49 x ( 17 + 37 ) + 54 x ( 26 + 25 )
= 49 x 54 + 54 x 51
= 54 x ( 49 + 51 )
= 54 x 100
= 5400
c) 14 x 35 x 5 + 10 x 25 x 7 + 20 x 70
= 70 x 35 + 10 x 25 x 7+ 20 x 70
= 70 x 35 + 250 x 7 + 20 x 70
= 70 x 35 + 70 x 25 + 20 x 70
= 70 x (35+25+20)
= 70 x 80
= 5600
Thực hiện dãy tính:
a) ( 1/2 - 1/7 ) + -1/3 . 3 4/7 - 0.75
b) ( 6/14 - -18/36 - 5/15 ) : ( 0,2 - 1 4/ 5 )
c) 11/ 32 : ( 14/18 + 16/27) - (2/3 - 5/15 )
d) 4. ( -1/2 ) 2 - 2. ( - 2/3 ) 2 + 2 7/9 - (-18/48)
e) 1,4 . 15/49 - (4/5 + 2/3 ) : ( -2 1/5 )
g) -1/7. (9 1/2 - 8.75 ) : 2/7 + 0,675 : ( -1 2/3 )
Tính:
a) 5-14+52-4+14-51+4
b)-/-13/-(-20)+13+(-20)-8
c)34-(-18)+/-5/-18+(-34)
d) -/-49/+(-42) - (-50)+43
e) 48 - (-52) + 64 + (-34)
làm rõ ràng chi tiết dùm mk nha, cảm ơn các bạn
Rút gọn các phân số sau:
a ) 9.6 − 9.3 18 ; b ) 17.5 − 17 3 − 20 ; c ) 49 + 7.49 49
d ) 9 13.3 2 − 4.3 2 ; e ) ( − 5 ) .4 + 8. ( − 7 ) ( − 12 ) .5 + 7.4 ; f ) ( − 14 ) .11 + 14.2 11.21 − 7.22
a) 3 2
b) -4
c) 8
d) 1 9
e) 19 8
f) − 18 11
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Diện tích hình bình hành có độ dài đáy 14 cm, chiều cao 7 cm là:
A. 49 cm2 B. 49 cm C. 98 cm2 D. 98 cm
Tính sau khi bỏ dấu ngoặc
a) (13+49) - (13-135+49)
b)(18+29)+(158-18-29)
c)4 .5 mũ 2 -3 . (24-9)
d)[ 93- (20-7)] :16
a)(13+49)-(13-135+49)
=13+49-13+135-49
=13-13+49-49+135
=0+0+135
=135
b)(18+29)+(158-18-29)
=18+29+158-18-29
=18-18+29-29+158
=0+0+158
=158
c)4 .52-3 .(24-9)
=4. 52- (3.24-3.9)
=4. 52-3.24+3.9
=4.25-72+27
=100-72+27
=28+27
=55
d)[93-(20-7)]:16
=(93-20+7):16
=80:16
=5
chúc cậu hok tốt
a) (13 + 49) - (13 - 135 + 49)
= 13 + 49 - 13 + 135 - 49
= (13 - 13) + (49 - 49) + 135
= 0 + 0 + 135
= 135
b) (18 + 29) + (158 - 18 - 29)
= 18 + 29 + 158 - 18 - 29
= (18 - 18) + (29 - 29) + 158
= 0 + 0 + 158
= 158
c) 4.52 -3.(24 - 9)
= 4.25 - 3.15
= 100 - 45
= 55
d) [93 - (20 - 7)] : 16
= [93 - 13] : 16
= 80 : 16
= 5
a,\((13+49)-(13-135+49)\)
\(=13+49-13-135+49\)
\(=(13-13)+(49-49)+135\)
\(=0+0+135\)
\(=135\)
\(b,(18+29)+(158-18-29)\)
\(=18+29+158-18-29\)
\(=(18-18)+(29-29)+158=0+0+158=158\)
c,Tự làm
d,\([93-(20-7)]:16\)
\(=(93-13):16=\frac{80}{16}=5\)
TÍNH A=[(1/4*9)+(1/9*14)+(1/14*19)+...+(1/44*49)] x (1-3-5-7-...-49)/89