Answer: (x - 3)² = 21
<u>Step-by-step explanation:</u>
x² - 6x + ____ = 12 + ____
↓ ↑ ↑

x² - 6x + <u> 9 </u> = 12 + <u> 9 </u>
(x - 3)² = 21
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Answer: (x - 6)² = 26
<u>Step-by-step explanation:</u>
2x² - 24x = -20
<u>÷2 </u> <u> ÷2 </u> <u> ÷2 </u>
x² - 12x = -10
x² - 12x + ____ = -10 + ____
↓ ↑ ↑

x² - 12x + <u> 36 </u> = -10 + <u> 36 </u>
(x - 6)² = 26