How do you solve #(2a^{2} + 8a - 5) + ( - 3a^{2} + 2a - 7)#?

1 Answer
Sep 14, 2016

#5 +- sqrt13#

Explanation:

Combine like terms:
#-a^2 + 10a - 12 = 0#
Solve this quadratic equation by the improved quadratic formula in graphic form (Socratic Search)
#D = d^2 = b^2 - 4ac = 100 - 48 = 52# --> #d = +- 2sqrt13#
There are 2 real roots:
#x = -b/(2a) +- d/(2a) = -10/-2 +- 2sqrt13/2 = 5 +- sqrt13#