Question

Đã trả lời bởi chuyên gia

Answer 1

$a) 5 (x + 3) - 2 x (3 + x) = 0 \Leftrightarrow 5 (x + 3) - 2 x (x + 3) = 0 \Leftrightarrow (x + 3) . (5 - 2 x) = 0 \Leftrightarrow x + 3 = 0 h o ặ c 5 - 2 x = 0 \Leftrightarrow x = - 3 h o ặ c 2 x = 5 \Leftrightarrow x = - 3 h o ặ c x = \frac{5}{2} V ậ y x = - 3 h o ặ c x = \frac{5}{2} b) 4 x (x - 2013) - x + 2013 = 0 \Leftrightarrow 4 x (x - 2013) - (x - 2013) = 0 \Leftrightarrow (x - 2013) . (4 x - 1) = 0 \Leftrightarrow x - 2013 = 0 h o ặ c 4 x - 1 = 0 \Leftrightarrow x = 2013 h ặ c 4 x = 1 \Leftrightarrow x = 2013 h o ặ c x = \frac{1}{4} V ậ y x = 2013 h o ặ c x = \frac{1}{4} c) (x ² + 1) (x - 2) + 2 x = 4 \Leftrightarrow (x ² + 1) (x - 2) + 2 x - 4 = 0 \Leftrightarrow (x ² + 1) (x - 2) + 2 (x - 2) = 0 \Leftrightarrow (x - 2) . (x^{2} + 1 + 2) = 0 \Leftrightarrow (x - 2) . (x^{2} + 3) = 0 \Leftrightarrow x - 2 = 0 h o ặ c x^{2} + 3 = 0 (l o ạ i v ì x^{2} + 3 > 0 \forall x \in ℝ) \Leftrightarrow x = 2 V ậ y x = 2$ .

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Answer 2

$a) 5 (x + 3) - 2 x (3 + x) = 0 \Leftrightarrow 5 (x + 3) - 2 x (x + 3) = 0 \Leftrightarrow (x + 3) . (5 - 2 x) = 0 \Leftrightarrow x + 3 = 0 h o ặ c 5 - 2 x = 0 \Leftrightarrow x = - 3 h o ặ c 2 x = 5 \Leftrightarrow x = - 3 h o ặ c x = \frac{5}{2} V ậ y x = - 3 h o ặ c x = \frac{5}{2} b) 4 x (x - 2013) - x + 2013 = 0 \Leftrightarrow 4 x (x - 2013) - (x - 2013) = 0 \Leftrightarrow (x - 2013) . (4 x - 1) = 0 \Leftrightarrow x - 2013 = 0 h o ặ c 4 x - 1 = 0 \Leftrightarrow x = 2013 h ặ c 4 x = 1 \Leftrightarrow x = 2013 h o ặ c x = \frac{1}{4} V ậ y x = 2013 h o ặ c x = \frac{1}{4} c) (x ² + 1) (x - 2) + 2 x = 4 \Leftrightarrow (x ² + 1) (x - 2) + 2 x - 4 = 0 \Leftrightarrow (x ² + 1) (x - 2) + 2 (x - 2) = 0 \Leftrightarrow (x - 2) . (x^{2} + 1 + 2) = 0 \Leftrightarrow (x - 2) . (x^{2} + 3) = 0 \Leftrightarrow x - 2 = 0 h o ặ c x^{2} + 3 = 0 (l o ạ i v ì x^{2} + 3 > 0 \forall x \in ℝ) \Leftrightarrow x = 2 V ậ y x = 2$ .

Answer 3

$a) 5 (x + 3) - 2 x (x + 3) = 5 (x + 3) - 2 x (x + 3) = (x + 3) (5 - 2 x) = > x + 3 = 0 v à 5 - 2 x = 0 = > x = - 3 v à x = \frac{5}{2} V ậ y x \in \{- 3; \frac{5}{2}\} b) 4 x (x - 2013) - x + 2013 = 0 4 x (x - 2013) - (x - 2013) = 0 (x - 2013) (4 x - 1) = 0 = > x - 2013 = 0 v à 4 x - 1 = 0 = > x = 2013 v à x = \frac{1}{4} V ậ y x \in \{\frac{1}{4}; 2013\}$

mik chỉ làm đc 2 câu thôi ạ

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Answer 4

$a) 5 (x + 3) - 2 x (x + 3) = 5 (x + 3) - 2 x (x + 3) = (x + 3) (5 - 2 x) = > x + 3 = 0 v à 5 - 2 x = 0 = > x = - 3 v à x = \frac{5}{2} V ậ y x \in \{- 3; \frac{5}{2}\} b) 4 x (x - 2013) - x + 2013 = 0 4 x (x - 2013) - (x - 2013) = 0 (x - 2013) (4 x - 1) = 0 = > x - 2013 = 0 v à 4 x - 1 = 0 = > x = 2013 v à x = \frac{1}{4} V ậ y x \in \{\frac{1}{4}; 2013\}$

mik chỉ làm đc 2 câu thôi ạ

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