Tìm x
a) X + 15 = 20 b) X – 18 = 16 c) 72 – x = 50
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d) X x 7 = 42 e) X : 7 = 5 f) 49 : x = 7
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tính nhanh:
a) 9 x 2 : 2
b) 45 : 9 x 9
c) 10 + 12 + 14 + 16 + ... + 80
d) 217 x 45 + 50 x 217 + 207 x 5
e) 3 x 9 + 18 x 2 + 2 x 9 + 9
g) 2006 x (43 x 10 -2 x 43 x 5) + 100
h) 64 x 4+8 x 3 + 8 + 8 + 8
i) 44 x5 +18 x 10 + 20 x 5
k) 3 x 4 + 4 x6 + 9 x 2 + 18
l) 2 x 5 + 5 x 7 + 9 x 3
Tìm x
a) 12 : x = 3 b) 21 : x = 7 c) 30 : x = 3
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d) X : 7 = 4 e) 20 : x = 5 f) X x 6 = 42
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Tìm x biết:
a, x – 28 = 750
b, x + 211 = 619
c, x – 20 = 830
d, x + 16 = 106
Tìm x biết:
a, (x - 32) ÷ 7 = 64
b, 24 ÷ (x - 12) = 4
Tính nhanh
a. 54 x 113 + 45 x 113 + 113
b. 54 x 47 - 47 x 53 - 20 - 27
Tìm x
a) x - 452 = 77 + 48
b) x + 58 = 64 + 58
c) x - 1 - 2 - 3 - 4 = 0
Tìm x: a.( 35 649 + 42 783 ) : x = 8 b.( 45 - 36 ) x X =63 117
Tìm x
a) x x 4 =64 b) 405 : x = 5
Tìm x biết:
a, x ÷ 7 = 25
b, x × 6 = 54