How do you solve #x^2+ 7x = - 10#?

Question

2697 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-05-09T15:21:01

The solutions are:

#x = -2 #

#x= - 5#

#x^2 + 7x = -10 #

#x^2 + 7x + 10 =0 #

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

#a=1, b=7, c=10#

The Discriminant is given by:

#Delta=b^2-4*a*c#

# = (7)^2-(4* 1 * 10)#

# = 49 - 40 = 9 #

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

#x = ((-7)+-sqrt(9))/(2*1) = ((-7+-sqrt9))/2#

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

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

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