Tìm x biết:
a, (x + 72) × 4 = 320
b, (x - 56) × 7 = 749
c, (x + 3) × 4 = 36
d, (x - 5) × 6 = 72
Tìm x biết:
a, (x + 9)×9 = 81
b, (x + 24)÷9 = 7
c, x - 56 = 8×9
d, x + 25 = 9×10
a .(18 – 9 x 2) x (2 + 4 + 6 + 8 + 10)
b.(7 x 8 – 56 ) : (2 + 4 + 6 + 8 + 112)
c. (2 + 125 + 6 + 145 + 112) x (42 – 6 x 7)
d.(12 x 6 – 12 x 4 – 12 x 2) x ( 347 + 125)
e(a x 7 + a x 8 – a x 15) : (1 + 2 + 3 + ........ + 10)
f.58 – 58 x (6 + 54 – 60)
g.32 + 63 x a x ( a x 1 – a : 1) + 32 x 8 + 32
h.(1 + 2 + 3 + 4 + .... + 9) x (21 x 5 – 21 – 4 x21)
i.(9 x 7 + 8 x 9 – 15 x 9) : (1 + 3 + 5 + 7 + ........+ 17 + 19)
k.(2 + 4 + 6 + 8 + ... + 20) x (56 x 3 – 72 : 9 x 21)
Tính nhẩm
9 x 5 =
63 : 7 =
8 x 8 =
5 x 7 =
8 x 7 =
3 x 8 =
40 : 5 =
5 x 5 =
7 x 5 =
7 x 8 =
6 x 4 =
45 : 9 =
7 x 7 =
35 : 5 =
56 : 8 =
2 x 8 =
81 : 9 =
9 x 9 =
35 : 7 =
56 : 7 =
a) 7 x 5 = ..... 7 x 6 = ..... 7 x 8 = ..... 7 x 4 = .....
35 : 7 = ..... 42 : 7 = ..... 56 : 7 = ..... 28 : 7 = .....
b) 42 : 7 = ..... 35 : 7 = ..... 63 : 7 = ..... 16 : 2 = .....
14 : 7 = ..... 49 : 7 = ..... 7 : 7 = ..... 48 : 6 = .....
28 : 7 = ..... 70 : = ..... 21 : 7 = ..... 56 : 7 = .....
Tìm x biết:
a, (x-23)×7 = 49
b, 25÷(x-56) = 5
1. Tìm x
a, x + 65 = 67 - 56
b, 12 - x = 5 x 6
2. Tính nhanh
1+ 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = ?
Tính nhẩm
7 x 8 =……………. 5 x 6 =…………..
56 : 7 =………….. . . 30 : 5 =…………..
56 : 8 = …………… 30 : 6 =…………..
Tìm x biết:
a, (x + 15)÷8 = 7
b, (x - 23)÷8 = 12
c, 24 = (x + 5)÷5
d, (x - 8)÷7 = 11
Tính nhẩm:
6 x 9 =
28 : 7 =
7 x 7 =
56 : 7 =
7 x 8 =
36 : 6 =
6 x 3 =
48 : 6 =
6 x 5 =
42 : 7 =
x 5 =
40 : 5 =