− 2 3 4 = ( − 2 ) 4 3 4 = 16 81 ; − 1 3 3 = ( − 1 ) 3 3 3 = − 1 27
− 1 5 7 2 = − 12 7 = 144 49 ; = − 2 5 5 = 16 625 - 1 , 34 o ; = 1
− 2 3 4 = ( − 2 ) 4 3 4 = 16 81 ; − 1 3 3 = ( − 1 ) 3 3 3 = − 1 27
− 1 5 7 2 = − 12 7 = 144 49 ; = − 2 5 5 = 16 625 - 1 , 34 o ; = 1
Tính
a) 5/2 -3,4 (12) -4/3 +1/3 .[ 1/2+0,5 -7/2]
b) [ 0,(5) .0(2) ] : [ 10/3 : 33/25 ] - [ 2/5 .4/3 ] : 4/3
a/4 =b/6 ;b/5 =c/8 vaf 5a -3b-3c
3a -5b +7c =86 vaf a+3/5 =b-2/3 =c-1/7
a-2b +c =46 vaf a/7 =b/6;b/5 =c/8
5a =8b =3c vaf a-2b +c =34
a^2 +3b^2 -2c^2 =-16 vaf a/2=b/3=c/4
(2/5 -x) :4/3 +1/2 =-4
(-3 +3/x -1/3 ) : ( 1+ 2/5 +2/3 ) =-5/4
-3x/4 .(1/x +2/7 )=0
1.tính
a) 3 -(-2/7)^0 + (1/2)^2 chia 2
b) (5^2) -(-5^2)+ ((-2)^3)^2
C) 2^3 + 3(1/2)^0 - 2^-2 . 4+[(-2)^2 chia 1/2 ] .8
d) 2^2 - 2^3 +2^4 +2^5 +.........+2^44+2^45
Chứng minh rằng:
A = 1/3 + 1/32 + 1/33 + ..........+ 1/399 < 1/2
B = 3/12x 22 + 5/22 x 32 + 7/32 x 42 +............+ 19/92 x 102 < 1
C = 1/3 + 2/32 + 3/33 + 4/34 +.........+ 100/3100 ≤ 0
|2 + 3x| = |4x - 3|
|3/2x + 1/2| = |4x - 1|
|5/4x - 7/2| - |5/8x + 3/5| = 0
|7/5x + 3/2| - |4/3 - 1/4| = 0
tính nhanh
(1+2+3+4+5+6+7+8+9).(1/2-1/3-1/4-1/5-1/6-1/7-1/8-1/9-1/0) /123
Bài 1: Tính
a) -7/9 . 2/3/4 (2/3/4 là hỗn số : 2 là số nguyên, 3/4 là phân số)
b) 2/3 + 1/3 . (-2/5)
c) 3/4 . 15/1/3 - 3/4 . 43/1/3
d) (-49,1) . 13/27 - 58,9 . 13/27
e) 0,375 : (-4,5)
f) 3/1/7 : (-1/3/7)
g) 9/1/3 : 4/2/3 - 2
h) (7/3/4 : 0,3125 + 4,5 . 2/2/45) : (-8,5)
Bài 2: Tính giá trị biểu thức
A = (-6/11) . 7/10 . (11/-6).(-20)
B = (-1/9) . (-17/29) . 58/51
C = (-3/7) . 5/11 + (-5/14) . 5/11
D = (1/1/27 . 12/23 . 9/14) : (-3/23)
Bài 3: Tìm x
a) 3/7 . x - 2/5 . x = -17/35
b) (3/4 . x -9/16) . [1/3 + (-3/5) : x] = 0
c) (x + 3/5) . (x + 1) = 0
2(x+1)-4x=6
3(2-x)+4(5-x)=4
7/3(x-4/3)+2/5(4-1/3x)=0
(x+1)(x-3) =0
nhanh giúp mik nha
( 2/5-x ) : 4/3 +1/2 =-4
( -3 +3/x -1/3 ) : (1+ 2/5 +2/3 ) =-5/4
-3x /4 .( 1/x +2/7 )=0