Answer:
16 will be added.
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.