Question

X^2-10x=1 Solve by completing the square

Answer 1

-0.0990195 and 10.09902

Explanation:

To complete the square, the same value needs to be added to both sides

x^2-10x+?=1+?

To complete the square x^2-10x+25=(x-5)^2 add 25 to the expression.

x^2-10x+25=1+?

Since 25 was added to the left-side, you need to add it to the right-side as well.

x^2-10x+25=1+25

use a^2-2ab+b^2=(a-b)^2 to factor this expression.

(x-5)^2=1+25

Then add the numbers together.

(x-5)^2=26

Solve for x.

x1=-squareroot26+5

x2=squareroot26+5

therefore you have 2 solutions

x1=-squareroot26+5

=-0.0990195

and

x2=squareroot26+5

=10.09902

Answer 2

x = 5±sqrt(26)

Explanation:

x^2-10x=1

Take the coefficient of x

-10

Divide by 2

-10/2 = -5

Square it

(-5)^2 = 25

Add this to both side

x^2-10x+25=1+25

(x-5)^2 = 26

Take the square root of each side

sqrt((x-5)^2) = ±sqrt(26)

x-5 = ±sqrt(26)

Add 5 to each side

x = 5±sqrt(26)