How do you solve #8x^2 - 10x - 25 = 0 #?

1 Answer
Apr 29, 2016

Answer:

#-5/4 and 5/2#

Explanation:

#y = 8x^2 - 10x - 25 = 0#
Use the new Transforming Method (Google, Yahoo Search)
Transformed equation #y' = x^2 - 10x - 200 = 0#
The 2 roots of y' have opposite signs because ac < 0.
Factor pairs of (ac = -200) -->...(-5, 40)(-10, 20). This last sum is 10 = -b. Therefor the 2 real roots of y' are: -10 and 20.
Back to original y, the 2 real roots are:
#x = -10/8 = - 5/4# and #x = 20/8 = 5/2#