1 Tính
a) -3 - 18
b) (-7).(-5)
c) 5+(-11)
2 Tính
a) -2-13+(-14)-19
b) 221 + 4[(-5).8-4]
c) (-2)3.(-2)2+32
d) -15.12 - 8.(-12)
3 Tìm x thuộc Z biết
a) x : (-2)=9
b) 4x + (-8)=24
c) (3x) (x+7)=0
1. Tính
a) 5/7 x 4 : 5/9
b) 8 x 2/3 : 1/2
c) 6 : 3/5 - 7/6 x 6/7
21/5 x 10/11 + 57/11
2. Tìm x
a) 35/9 : x = 35/6
b) (1/1x2 + 1/2x3 + 1/3x4 +1/4x5 +1/5x6) x 10- x = 0
a, 2 1/3 + 1 3/5 = b, 4 5/9 - 2 5/6 = c, 3 2/4 x 2 2/7 = d, 4 2/5 : 4 1/8 =
Bài 2: Viết tiếp 2 số hạng vào dãy số sau:
a) 10, 13, 18, 26, ...
b) 0, 1, 2, 4, 7, 12, ...
c) 0, 1, 4, 9, 18, ...
d) 5, 6, 8, 10, ...
e) 1, 6, 54, 648, ... ...
k) 1, 3, 3, 9, 27,
L) 1, 2, 3, 6, 12, 24....
m) 1, 4, 9, 16, 25, 36,
o) 2, 12, 30, 56, 90,
p) 1, 3, 9, 27, ....
g) 1, 5, 14, 33, 72, h) 2, 20, 56, 110, 182.....
q) 2, 6, 12, 20, 30, ...
t) 6, 24, 60, 120, 210...
tinh
a) 3/5 x 7/8 : 10/9
b) 3 2/7 x 2 1/4 : 1 2/5
c) 6/9 + 24/15 + 12/9 + 6/15
d) 3 2/9 - ( 1 5/8 + 1 2/9 )
a. 2+3/4 b.1/3+3/2-7/4 c.1/6+3/8-1/4 d.5/12+3/8x4/9 e.4/5-1/5x7/2 f.16/9-4/15:2/5
a) 3/5 + 4/3
b) 2/3 - 1/5
c) 1/2 + 1/3 + 1/6
d) 3/5 + 4/7 + 7/5 + 3/7
e) 1/5 + 2/9 + 7/9 + 4/5 + 16/17 + 1
f) 1/3 x 2/7 + 1/3 x 5/7 + 15/9
Bài5:Tính
a,2/3 + 1/6 - 5/12,1/4+1/2-1/8
b,1/4+1/2-1/8
c,5/8+3/4×1/2
d,1/4+7/24×3/12
e,5/6×3/4:15/24+1/2,14/15:10/12×5/7+1/3
A) 4 3/8+5 2/3-9 25/24 B) 2 3/8+1 1/4+3 6/7=3 5/8+3 6/7=7 29/56 C) 2 3/8-1 1/4+5 1/3