( x+2/9) 5= (x+2/5)3
2/25.
C)-1/4+-5/17.[1/3:20/17.
5.tính nhanh a)-3/7+5/13+-4/7
B) 5/9+7/12+4/9
C) 9/10.-7/8+9/10.-1/8
D 7/19.8/11+7/19.3/11+12/19.
6 . tim x
A) X+1/7=-2/3.
B)5/9+7/12+4/9.
C)-1/3.x5/7.
D)x:-5/9=9/10
E)x/3=2/3+-1/7.
7)qua da hau nang bao nhieu kilogam neu biet 2/3qua dau nang .1, 2 phan 3 kg?
8biet ti so phan tram nUoc tong dua cHuot la 97,2%tinh luong nuoc trong 4 kg dua chuot.
3) tim so tu nhien x biet
a) 450 : (3-19 )=50
b )3^2 x( x +4 ) -5^2 =5x 2^2
c )7x = 511: 5^9 +3^1
d) 6x =68 -2^ 19 :2^16
tìm x
a, x + 1/2x - 25%x = 10
b, x+x - 1+ x - 2 + x -3 + x - 4 + ... + x-50 = 255
c, 1 + 5 + 9 + 13 + 16 + ... + x =501501
Câu 1
a)(-9)+(-3)
b)6.7.52+42.75
c)4529-(186+4529)
Câu 2
a)x-7=15
b)9+4.(x-5)=17
c)(x-3)3=27
Bài 1:Tính nhanh
a) 14 : (4\(\frac{2}{3}\)-1\(\frac{5}9\)) + 14 : (\(\frac{2}3\)+\(\frac{8}9\))
b)\(\frac{1212}{1515}\)+\(\frac{1212}{3535}\)+\(\frac{1212}{6363}\)+\(\frac{1212}{9999}\)
Bài 2:Tìm x
(x + 1) + (x + 2) +.........+ (x + 211) = 23632
1, Tính:
\(\dfrac{7256.4375-725}{3650+4375.7255}\)
2, Tìm x biết:
a, (3x-4).(x-1)3=0
b, 22x-1:4=83
c, (x-5)4-(x-5)6
d, (x+2)5=210
e, (3x-24).73=2.74
f, (x+1)2=(x+1)0^0
3. Rút gọn:
a, -(-a+c-d)-(c-a+d)
b, (a+b)-(a-b)
4, Tìm x, y thuộc N biết:xy+x+2y=5
Tìm STN x biết.
70 - 5. (X-3) = 45
12+ (5+x) = 20
130-( 100+x) = 25
175 + (30 - x) = 200
5(x + 12) + 22 = 92
95-5(x+2) = 45
14x +54 = 82
15x -133 = 17
155-10(x + 1) = 55
1 thực hiện phép tính
3/4 -1 1/2 (hỗn số) +50% :5/12
1 5/9( hỗn số) -1/2.(1/2-1/4-1/12) - -2/3
1,25:15/20 (25% -5/6):4 2/3
