A/(X-21x13 ):11 = 30 B;/(627-138):(x:2) = 163 (1/2 +x.9/7):2 =1
TÌM X : (X-21x13):11+39
Tìm X,biết: (X-21x13):11+39
x- [21x13:11 =39 [X-21x13] ;19=39
5x(13-26)-26x(13-5)+21x13
\(5.\left(13-26\right)-26.\left(13-5\right)+21.13\)
\(=65-130-338+130+273\)
\(=0\)
5.(13-26)-26.(13-5)+21.13
= 5.(-13)-26.8+273
= (-65)-208+273
= (-273)+273
= 0
đúng thì **** nha
Bài 1 tìm X
a) X-140:35=270
b) 180-(X-45):2=120
c) X:15+42=15+25x8
d) (X+40)x15=75x12
e) 1,2 x X- 4,68:1,3:1,2=0,6
g)2,4: (2-X)-0,32x4,5=1,56
h) ¾-(X-1)=1/2
k) 5/3-( 3xX+0,5)=2/3
Bài 2 tìm x
a) (X-21x13):11=30
b) (627-138):(x:2)=163
c) (1/2+X.9/7):2=1
Bài 3
1)576:X-30=2
2)112-(x+4)=1339:13
3) (2x-26):2=6
4) 15x (3xX-6)=0
5) (X-21)x13:11=39
6)80-(X-45):2=120
7) (627-138) : (X:2)=163
8) 15x(32-24:X)-230=70
63x(64-62)+62x(62-64)
5x(13-26)-26x(13-5)+21x13
63x(64-62)+62x(62-64)
=63x2+62x2
=(63+62)x2
=125x2
=250
Bài 1 tìm X
a) X-140:35=270
b) 180-(X-45):2=120
c) X:15+42=15+25x8
d) (X+40)x15=75x12
e) 1,2 x X- 4,68:1,3:1,2=0,6
g)2,4: (2-X)-0,32x4,5=1,56
h) ¾-(X-1)=1/2
k) 5/3-( 3xX+0,5)=2/3
Bài 2 tìm x
a) (X-21x13):11=30
b) (627-138):(x:2)=163
c) (1/2+X.9/7):2=1
Bài 3
1)576:X-30=2
2)112-(x+4)=1339:13
3) (2x-26):2=6
4) 15x (3xX-6)=0
5) (X-21)x13:11=39
6)80-(X-45):2=120
7) (627-138) : (X:2)=163
8) 15x(32-24:X)-230=70
bài 1 :
a, x - 140 : 35 = 270
x - 4 = 270
x = 270 + 4
x = 274
b, 180 - ( x - 45 ) : 2 = 120
( x - 45 ) : 2 = 180 - 120 = 60
x - 45 = 60 . 2 = 120
x = 120 + 45 = 165
c, x : 15 + 42 = 15 + 25 . 8
x : 15 + 42 = 15 + 200
x : 15 + 42 = 215
x : 15 = 215 - 42 = 173
x = 173 . 15 = 2595
d, ( x + 40 ) . 15 = 75 . 12 = 900
x + 40 = 900 : 15 = 60
x = 60 - 40 = 20
e, 1,2x - 4,68 : 1,3 : 1,2 = 0,6
1,2x - 3 = 0,6
1,2x = 0,6 + 3 = 3,6
x = 3,6 : 1,2 = 3
g, 2,4 : ( 2 - x ) - 0,32 x 4,5 = 1,56
2,4 : ( 2 - x ) - 1,44 = 1,56
2,4 : ( 2 - x ) = 1,56 + 1,44 = 3
2 -x = 2,4 : 3 = 0,8
x = 2 - 0,8 = 1,2
h) 3/4 - ( x - 1 ) = 1/2
3/4 - x + 1 = 1/2
3/4 - x = 1/2 + 1 = 3/2
x = 3/4 - 3/2 = -3/4
k) 5/3 - ( 3x + 0,5 ) = 2/3
3x + 0,5 = 5/3 - 2/3 = 1
3x = 1 - 0,5 = 0,5
x = 0,5 : 3 = 1/6
mỏi tay qá
Tính nhanh:
a, ( 21,4 x 35,5 - 25,5 x 21,4 ) x ( 15x12 - 1500 x 0,1 - 30)
b, D=11+11/2+11/6+11/12+11/20+...+11/110
Tìm x,y:
a, (x-2).(y+1)=11
b, x.y=30 và x+y=-11