Describe and correct the error Solve x3 20x 2x3 7x 3x3 2

Describe and correct the error. Solve x^3 + 20x = -2x^3 - 7x 3x^3 + 27x = 0 3x(x^2 + 9) = 0 3x(x-3)(x + 3)=0 x={-3, 0, 3}

Solution

x³ +2x³ +20x +7x =0

x(3x² + 27) = 0

3x(x² + 9) =0

x² + 9 is not equal to (x-3)(x+3)

x =0 is root and (x²+ 9) =0

x ² = -9

x = 3i ,-3i

solution : x = {0 ,3i ,-3i}