How do you solve #x^2 – 10x – 1 = -10# using the quadratic formula?

1 Answer
Aug 14, 2017

Answer:

#x=9,1#

Explanation:

Given:

#x^2-10x-1=-10#

Move all terms to the left side.

#x^2-10x-1+10=0#

Simplify.

#x^2-10x+9# #larr# Quadratic equation in standard form:

#ax^2+bx+c=0#, where:

#a=1#, #b=-10#, and #c=9#.

Quadratic formula

#x=(-b+-sqrt(b^2-4ac))/(2a)#

Substitute the given values into the formula.

#x=(-(-10)+-sqrt((-10)^2-4*1*9))/(2*1)#

Simplify.

#x=10+-sqrt(100-36))/2#

Simplify.

#x=(10+-sqrt64)/2#

#x=(10+-8)/2#

Solutions for #x#.

#x=(10+8)/2,# #(10-8)/2#

Simplify.

#x=18/2,# #2/2#

#x=9,1#