a) x.(x+7) = 0
=> x = -7
b) ( x+12 ) . ( x-3) = 0
a, x.(x+7)=0
suy ra: x=0 or x+7=0
suy ra:x=0 or x=-7
b,(x+12).(x-3)=0
suy ra : x+12=0 or x-3=0
suy ra : x=-12 or x=3
a,\(x\in\left\{0;-7\right\}\)
b,\(x\in\left\{-12;3\right\}\)
a) x.(x+7) = 0
=> x = -7
b) ( x+12 ) . ( x-3) = 0
a, x.(x+7)=0
suy ra: x=0 or x+7=0
suy ra:x=0 or x=-7
b,(x+12).(x-3)=0
suy ra : x+12=0 or x-3=0
suy ra : x=-12 or x=3
a,\(x\in\left\{0;-7\right\}\)
b,\(x\in\left\{-12;3\right\}\)
Tìm x∈Z, biết:
a)x.(x-6)=0
b)(-7-x).(-x+5)=0
c)(x+3).(x-7)=0
d)(x-3).(x2+12)=0
e)(x+1).(2-x) ≥0
f)(x-3).(x-5) ≤0
2. Tìm x:
a) 4/5 + x = 2/3
b) 1/2 - x = 7/12
c) 3 và 1/2 : x = -7/2
d) 3/8 - 1/6 x =5/2
e) x + 50%x = -1,5
Tìm x:
a, (-5) +x = 7
b, (-14) - x + (-15) = -10
c, 12 + x (-5) = -18
d, x - (-19) - (-11) = 0
Tìm số nguyên x, biết:
a) (x + 12) . (x – 6) > 0
b) (10 - x) . (3 - x) < 0
Tìm x:a) x - 2 + 7 = 1 . 3 . -9
b) 4 . x - 1 = (-5) 5 12 2 4 16 9 2 9
c) -2 . x + 5 = 7
d) 2 . x : 7 . 1 = 29 3 8 12 5 3 8 15
Bài 2: Tìm x:
a) 156 – (x+ 61) = 82 b) (x-35) -120 = 0 c) 124 + (118 – x) = 217 d) 7x – 8 = 713 e) x- 36:18 = 12 f) (x- 36):18 = 12 g) (x-47) -115 = 0 |
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Bài 3: Tính nhanh
a) 58.75 + 58.50 – 58.25 b) 27.39 + 27.63 – 2.27 c) 128.46 + 128.32 + 128.22 d) 66.25 + 5.66 + 66.14 + 33.66 e) 12.35 + 35.182 – 35.94 | f) 48.19 + 48.115 + 134.52 g) 27.121 – 87.27 + 73.34 h) 125.98 – 125.46 – 52.25 i) 136.23 + 136.17 – 40.36 j) 17.93 + 116.83 + 17.23 | k) 35.23 + 35.41 + 64.65 l) 29.87 – 29.23 + 64.71 m) 19.27 + 47.81 + 19.20
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Bài 4: Tính giá trị của biểu thức sau:
a) 2763 + 152 b) (-7) + (-14) c) (-35) + (-9) d) (-5) + (-248) e) (-23) + 105 f) 78 + (-123) g) 23 + (-13) h) (-23) + 13 i) 26 + (-6) | j) 80 + (-220) k) (-23) + (-13) l) (-26) + (-6) | m) 12 – 34 n) -23 – 47 o) 31 – (-23) p) -9 – (-5) q) 6 – (8 – 17) r) 19 + (23 – 33) s) (-12 – 44) + (-3) t) 4 – (-15) u) -29 – 23 | v) 99 – [109 + (-9)] w) (-75) + 50 x) (-75) + (-50) y) (-23) + 13 + ( - 17) + 57 z) 14 + 6 + (-9) + (-14)
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Tìm x:a) x - 2 + 7 = 1 . 3 . -9
b) 4 . x - 1 = (-5) 5 12 2 4 16 9 2 9
c) -2 . x + 5 = 7
d) 2 . x : 7 . 1 = 29 3 8 12 5 3 8 15
Tim x:
a) 6 x X - 5 = 613 b) 12 x X + 3 x X = 30
C) 125 - 25 x (X - 1) = 100 d) ( X - 2 ) x 9 X - 4) = 0
Tìm x:
a, \(\left(12-12\dfrac{1}{3}\right):x+\dfrac{1}{6}=\dfrac{-2}{3}\)
b, \(\dfrac{4}{x}=\dfrac{x}{16}\)
Tìm x:a,42-42(x+1)=0. b ,(2x+4)-(x+3)=0