|-34|.x=(-12)+46
34 + 36 x 46 + 12
Tính bằng cách thuận tiện nhất :
12 + 34 + 88 + 46 + 55 + 34 + 65 + 46 = ???????????????????
=(12+88) +(34+46)*2+(55+65)=100+2*80+120=100+160+120=380
12 + 34 + 88 + 46 + 55 + 34 + 65 + 46
= (12 + 88) + (34 + 46) + ( 55 + 65) + ( 34 + 46)
= 100 + 80 + 120 + 80
= 380
[46+34]nhan 12 +9nhan `12+12
( 46 + 34 ) x 12 + 9 x 12 + 12
= 80 x 12 + 9 x 12 + 12 x 1
= 12 x ( 80 + 9 + 1 )
= 12 x 90
= 1080.
Chúc bạn học tốt!!!!!!!!!!!!!!
( 46 + 34 ) x 12 + 9 x 12 + 12 = 1080
( 46 + 34 ) x 12 + 9 x 12 +12 = 80 x 12 + 9 x 12 + 12 = 910 + 9 x 12 + 12 = 910 + 108 + 12 = 1018 + 12 = 1030 .
Tính : 12 x 23
34 x 46
64 x 45
12 x 23 = 276
34 x 46 = 1564
64 x 45 = 2880
12*23=276
34*46=1564
64*45=2880
nhớ tk nha cảm ơn
Tính nhẩm
46 x 99 34 x 11 25 x 12 15 x 4 45 x 6 13 x 99 16 x 19 35 x 98
125 x 16 47 x 101
\(46\cdot99\)
\(=46\cdot\left(100-1\right)\)
\(=46\cdot100-46\)
\(=4600-46\)
\(=4554\)
___________
\(34\cdot11\)
\(=34\cdot\left(10+1\right)\)
\(=34\cdot10+34\)
\(=340+34\)
\(=374\)
___________
\(25\cdot12\)
\(=5\cdot5\cdot12\)
\(=5\cdot60\)
\(=300\)
__________
\(15\cdot4\)
\(=15\cdot2\cdot2\)
\(=30\cdot2\)
\(=60\)
____________
\(45\cdot6\)
\(=45\cdot2\cdot3\)
\(=90\cdot3\)
\(=2700\)
________
\(13\cdot99\)
\(=13\cdot\left(100-1\right)\)
\(=13\cdot100-13\)
\(=1300-13\)
\(=1287\)
______________
\(16\cdot19\)
\(=16\cdot\left(20-1\right)\)
\(=16\cdot20-16\)
\(=320-16\)
\(=304\)
_____________
\(35\cdot98\)
\(=35\cdot\left(100-2\right)\)
\(=35\cdot100-35\cdot2\)
\(=3500-70\)
\(=3430\)
____________
\(125\cdot16\)
\(=125\cdot8\cdot2\)
\(=1000\cdot2\)
\(=2000\)
___________
\(47\cdot101\)
\(=47\cdot\left(100+1\right)\)
\(=47\cdot100+47\)
\(=4700+47\)
\(=4747\)
46 x 99 =4554 , 34 x 11 = 374 , 25 x 12 =- 300 , 15 x 4 = 60 , 45 x 6 = 270 , 13 x 99 = 1287 , 16 x 19 = 304
35 x 98 = 3430 , 125 x 16 = 2000 , 47 x 101 = 4747
Tính bằng cách thuận tiện nhất
a -(12/46 +15/21) +(3/7-7/23)
b(-21+-7/-9)-(6/34-25/9)
c (21/8--13/-26)+(34/16--12/52)
a) \(...=-\dfrac{12}{46}-\dfrac{15}{21}+\dfrac{3}{7}-\dfrac{7}{23}\)
\(=-\dfrac{12}{46}-\dfrac{7}{23}-\dfrac{15}{21}+\dfrac{3}{7}\)
\(=-\dfrac{6}{23}-\dfrac{7}{23}-\dfrac{5}{7}+\dfrac{3}{7}\)
\(=-\dfrac{13}{23}-\dfrac{2}{7}\)
\(=-\dfrac{13.7}{23.7}-\dfrac{2.23}{23.7}\)
\(=-\dfrac{91}{161}-\dfrac{46}{161}=-\dfrac{137}{161}\)
b) \(...=-21+\dfrac{7}{9}-\dfrac{3}{17}+\dfrac{25}{9}\)
\(=-21-\dfrac{3}{17}+\dfrac{7}{9}+\dfrac{25}{9}\)
\(=-21-\dfrac{3}{17}+\dfrac{32}{9}\)
\(=-\dfrac{3213}{153}-\dfrac{27}{153}+\dfrac{544}{153}=-\dfrac{2696}{153}\)
Tính các tổng sau:
a) 1 2 + 2 3 + 3 4 + 4 5 + 5 6
b) 4 6 + 27 81
a) 1 2 + 2 3 + 3 4 + 4 5 + 5 6 = 30 60 + 40 60 + 45 60 + 48 60 + 50 60 = 71 20
b) 4 6 + 27 81 = 4 6 + 2 6 = 1
x+34=67
x+12=46
x-13=1
x+560=685
ai nhanh mk sẽ tik , ai là Army thì kb nha !!! k pk cx đk
x=33
x=34
x=14
x=125
Mình cũng là army kb nha
a , x + 34 = 67
x = 67 - 34
x = 33
b , x + 12 = 46
x = 46 - 12
x = 34
c , x - 13 = 1
x = 13 + 1
x = 14
d , x + 560 = 685
x = 685 - 560
x = 125
Tk nha!! Mình kết bạn rồi .