How do you solve #5x^2+98=0# using the quadratic formula?

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Answer 1 · 2016-09-11T21:26:05

You don't need the quadratic formula. But here goes:

Answer is:

Equation not valid in #RR#

Quadratic solving

#5x^2+98=0#

This is the same as:

#5x^2+0x+98=0#

For #a=5# #b=0# #c=98# :

#Δ=b^2-4*a*c=0^2-4*5*98=-1960#

Since #Δ<0# the equation in impossible inside #RR#.

Simpler solution

#5x^2+98=0#

#5x^2=-98#

#x^2=-98/5#

No real number can have a negative square, therefore the equation in impossible inside #RR#.