a. 2/3 . ( x + 2 ) = 1/5x
2/3x + 2/3 . 2 = 1/5x
2/3x + 4/3 = 1/5x
2/3x + 4/3 - 1/5x = 0
7/15x + 4/3 = 0
7/15x = -4/3
x = -4/3 . 7/15
x = -20/7
b. x/4 = -2/7
x = -2/7 . 4
x = -8/7.
a. 2/3 . ( x + 2 ) = 1/5x
2/3x + 2/3 . 2 = 1/5x
2/3x + 4/3 = 1/5x
2/3x + 4/3 - 1/5x = 0
7/15x + 4/3 = 0
7/15x = -4/3
x = -4/3 . 7/15
x = -20/7
b. x/4 = -2/7
x = -2/7 . 4
x = -8/7.
tính giá trị của biểu thức
a) 5xa^5xb^4+4xa^4xb^3+3xa^3xb^2-2xa^2xb-axb^2+26-2xa tại a= -1; b=-1
a^10-a^9-a^8-a^7+a^6-a^5+a^4-a^3+a^2+a^1 tại a=-1 và a=1
a,1/3 .(x-2/5)=3/4 b, 7/3:(x-2/3)=4/5 c,1/3.(x-2/5)=4/5 d, 2/3.(x-1/2)-1/4.(x-2/5)=7/3 e,3/7 .(x-2/3)+1/2=5/4.(x-2) f,1/2.(x-3)+1/3.(x-4)+1/4.(x-5)=1/5 g,[2/3.(x-1/2)-4/5]:(x-1/3)=21/5 h, {x-[1/2.(x-3)+11/5]}:(x-1/2)=3/5 i,x.(x-2/5)-(x+2).x+11/4=4/3
a.2/3.x=4/7 b.-6/5.x=1/2 c.2/3.x=-1/4 d.3/4.x=2/-7
a,3/2(x+7)=x+7/6
b,9/4. /x/-4=1/4./x/
c,3/(-2)^2-(1/4-x)^2=1-1/2
Tim x biet
A 3/2.x-2/5=1/3.x-1/4
B -51/2.x+1=3/4-7/6
C 2.x-2/3=7.x+3/2-1
D 3/2.x-2/5=1/3.x -1/4
Tính :
a) 13/15 + 4/7 - 101/105 b) 2/5 + 3/5 + x 4/9 c) 3/4 x 5/2 x 7/6
d) 1/2 : 1/4 - 2/9 e) 2/3 - 1/4 +2/9 g) 5/2 + 1/3 x 3/2
a,x - 1/2 - (-1/6)
b,x + 5/6 = 3/8
c,2/3 . x -1/2 = 5/6
d, x/7 = 6/-21
e,(7/3 x -0,6) : 3^2/5 = 1
f,x/45 = 5/6 + -29/30
g,(4,5 - 2x) . (-1^4/7) =11/14
h,-2/7 + 4/7x=5/7
Tính nhanh :
a) 1 / 1 x 2 + 1/ 2 x 3 + 1/ 3 x 4 + .............................................................................................................. + 1 / 99 x100
b) 2 / 1 x 3 + 2 / 3 x 5 + 2 / 5 x 7 + ............................................................................................................ + 2 / 97 x 99
c) 4 / 5 x 7 + 4 / 7 x 9 + 4 / 9 x 11 + .......................................................................................................... + 4 / 59 x 61
Giúp mình nha mình tick cho.
A= ( 6 : 3/5 - 1 1/6 x 6/7 ) : ( 4 1/5 x 10/11 + 5 2/11 )
B= ( 1 - 1/2 ) x ( 1- 1/4 ) x ... x ( 1 - 1/2003 ) x ( 1 - 1/2004 )
C= 5 9/10 : 3/2 - ( 2 1/3 x 4 1/2 - 2 x 2 1/3 ) : 7/4