How do you solve #x^2 + 3x -10 =0# using the quadratic formula?

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Answer 1 · 2016-03-25T17:56:42

The solutions are:
#x= 2#

#x= -5#

#x^2 + 3x - 10= 0#

The equation is of the form #color(blue)(ax^2+bx+c=0# where:

#a=1, b= 3 , c= - 10#

The Discriminant is given by:

#color(blue)(Delta=b^2-4*a*c#

# = (3)^2-(4* 1 * ( -10))#

# = 9 + 40 = 49#

The solutions are found using the formula
#color(blue)(x=(-b+-sqrtDelta)/(2*a)#

#x = ((-3)+-sqrt(49))/(2*1) = (-3 +- 7 )/2#

#x= (-3 + 7 )/2 = 4/2 = 2#

#x= (-3-7)/2 = -10/2 = -5#