How do you solve #(10x + 3) ( 3x^{2} - 11x - 4) = 0#?

1 Answer
Sep 12, 2016

#-3/10, 1/3, and -4#

Explanation:

#f(x) = (10x + 3)(3x^2 - 11x - 4) = 0#
a. (10x + 3) = 0 --> #x = - 3/10#
b. Solve the quadratic equation by the new Transforming Method (Socratic Search):
#y = 3x^2 - 11x - 4 = 0#
Transformed equation #y' = x^2 - 11x - 12 = 0#
Since a + b + c = 0, use shortcut. The 2 real roots of y' are: 1 and
#c/a = - 12#. Divide them by a = 3 to get the 2 real roots of y.
They are: #x1 = 1/3# and #x2 = -12/3 = -4#.
Answers:
#-3/10, 1/3 and -4#