At least 15 b/c is you add QWERTY to -12, you get zero and adding 5 to get 15 in total.
Answer:

Step-by-step explanation:
observe
||a–b+c|| = ||a+b+c||
(a-b+c)² = (a+b+c)²
(a+b+c)² – (a-b+c)² = 0
((a+b+c)+(a-b+c))((a+b+c)–(a-b+c)) = 0
(2a+2c)(2b) = 0
(a+c)b = 0
a•b + c•b = 0
||a||×||b||×cos(π/8) + ||c||×||b||×cos(θ) = 0

Answer:
Hello, Friend! ^^
The Answer Is 13 Inches <3
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Hope this helps! ^^ :3