1-2+3-4+...-98+99
(-2003)+(-21+75+2003)
75.(-21)
(-15).(-17)
(-57),(67-34)-67.(34-57)
(-98).(1-246)-246.98
ai tra loi dung va nhanh minh tich nha 3 cai luon
15*37*4+120*21+21*5*12
15*(27+18+6)+15*(23+12)
10*(81+19)+100+50*(91+9)
42*(15+96)+6*(25+4)*7
16*(27+75)+8*(53+25)*2
Bài 1: Thay một thừa số bằng tổng để tính:
a) - 57 . 11 b) 75 . (-21)
Bài 2: Tính nhanh:
a) (- 4) . (+ 125) . (- 25) . (- 6) . (- 8)
b) (- 98) . (1 - 246) - 246 . 98
tINH NHANH
A ) 78. 123 + 88 .33 - 78 x 23 + 11.8.67
b)42 . 53 + 47.156 _ 114.47
c ) 53 . 39 + 39 . 47 - 15 . 21 - 7 . 155
d ))15 . 37 . 4 + 120 . 21 + 21 x 5 x12
e ) 2 . 53 . 12 4 . 6 . 87 _ 15 . 4
g ) (2500 + 75 ) : 25 - ( 36 . 11 ) : 1
1) 15 - 98 + 91 - 75 + 98 - 91 - 13
2) 5 - ( 4 - 7 + 12 ) + ( 4 - 7 + 12 ) - 10
3) 20 - ( 25 - 98 + 12 ) + ( 25 - 98 - 72 )
4) - ( 17 - 4 + 13 + | -17 | + 13 )
5) | -16 | - ( 5 - 8 + 7) - ( - 5 ) - 8
6) -20 + ( 3 - 16 + 7 ) - ( 3 - 16 + 7 )
7) 32 - ( 5 - 8 + 32 ) + ( 5 - 8 + 6 )
8) -20 - ( 25 - 11 + 8 ) + ( 25 - 8 + 20 )
(x – 15 ) – 75 = 0 b) 575- (6x +70) =445
c) x –105 : 21 =15 d) (x - 105) :21 = 15
\(\frac{15}{21}+\frac{4}{42}\)
\(\frac{75}{100}-\frac{2}{4}\)
15/-21=-75/...
