How do you solve #x^2=121#?

1 Answer
Mar 10, 2018

Answer:

#x1 = -11,# #x2 = 11#

Explanation:

Move the constant to the left and change its sign

#x^2-121=0#

Using #a^2 - b^2 = (a - b) (a + b)#, Factor the expression

#(x - 11)(x + 11)=0#

When the product of factors equals 0, at least one factor is 0

#x-11=0#

#x+11=0#

Solve both equations for #x#

#x=11#

#x=-11#

The final solutions are

#∴# #x1=-11,# #x2=11#