0<a<b<c T/m |a^3-4a|=|b^3-4b|=|c^3-4c|. C/M a+b=c
Tham khảo câu trả lời từ Trợ lý ảo Lazi To solve the problem, we need to analyze the conditions given: 1. \( 0 < a < b < c \) 2. \( |a^3 - 4a| = |b^3 - 4b| = |c^3 - 4c| \) 3. \( a + b = c \) Given these conditions, we proceed as follows: The expression for each value can be rewritten as: \[ |x^3 - 4x| = k \] where \( k \) is a constant equal for \( a \), \( b \), and \( c \). Considering the expression \( |x^3 - 4x| = k \), we know it involves taking the absolute value, which implies: \[ x^3 - 4x = k \quad \text{or} \quad x^3 - 4x = -k \] Now let's test a simple rational solution to satisfy all the conditions: 1. Try a few small integer values or simple rational values for \( a \) to find \( k \), and see if the relations among \( a \), \( b \), and \( c \) are satisfied. For example, if \( a = 1 \): \[ |1^3 - 4 \times 1| = |-3| = 3 \] So, \( k = 3 \). Plug this into the equation: For \( b \): \[ |b^3 - 4b| = 3 \] and for \( c = a + b \): \[ |c^3 - 4c| = 3 \] Next, let's solve \( |x^3 - 4x| = 3 \): - \( x^3 - 4x = 3 \) gives the equation \( x^3 - 4x - 3 = 0 \) - \( x^3 - 4x = -3 \) gives the equation \( x^3 - 4x + 3 = 0 \) By solving these cubic equations, we find the possible \( x \) values that satisfy this: - For \( x^3 - 4x - 3 = 0 \), factoring or using the Rational Root Theorem gives a possible solution \( x = -1 \), which can be rejected since \( a, b, c > 0 \). - For \( x^3 - 4x + 3 = 0 \), solve for potential \( a, b, c \). Let's use the rational root test to verify possible roots or numerical approaches, but ideally: Assuming each is 1 for simplicity: \[ a = 1, b = 2, c = 3 \] Verify if this set works: \( a^3 - 4a = 1 - 4 = -3 \) \( b^3 - 4b = 8 - 8 = 0 \) (*Not fulfilled for \( b = 2 \)*) Thus given the symmetrical nature of these equations, practical whole integer roots for these conditions and constraints won't evenly satisfy them unless \( a, b, c \) are parts of roots in polynomial or irrational results. Therefore a deeper numeric computation or plotting tool should be engaged to solve. Explore further to find values where \( x^3 - 4x = \pm k \) and satisfy these conditions, potentially using numerical or graph solution methods to find valid \( b, a, \) such that \( c = a + b \).