To solve x2−8x=10 by completing the square, what should be added to both sides?

16 will be added.

Step-by-step explanation:

Given equation is,

x² - 8x = 10

To convert this equation into a square form we will follow the following steps,

Step (1). x² - 2(4x) = 10

Step (2). x² -2(x)(4) + 16 = 10 + 16

Step (3). x² - 2(4)(x) + 4² = 26

Step (4). (x - 4)² = 26

In step (2) we have added 16 to both the sides of the equation to make is a perfect square.