Answer:
The answer to your question is:
Step-by-step explanation:
12.-
x² - 6x = 5
x² - 6x + (3)² = 5 + (3)²
x² - 6x + 9 = 5 + 9
(x - 3)² = 14
13.- x² - 6x = 12
x² - 6x + (3)² = 12 + (3)²
x² - 6x + 9 = 12 + 9
(x - 3)² = 21
x - 3 = ±√21
x1 = √21 + 3 x2 = -√21 + 3
x1 = 7.58 x2 = -1.58
14.- 2x² - 24x = - 20 Divide by 2
x² - 12 x = -10
x² - 12x + (6)² = - 10 + (6)²
x² - 12x + 36 = - 10 + 36
( x - 6) ² = 26
x - 6 = ±√26
x1 = √26 + 6 x2 = -√26 + 6
x1 = 11.1 x2 = 0.9
