Answer:
- 3
- 7
- 7
Step-by-step explanation:
1. In 2 draws, you can get one of each, so a minimum of 3 draws will guarantee at least 2 of one color.
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2. A minimum of 3 socks must be drawn to ensure one pair. A minimum of 2 must be drawn to ensure an additional pair. For three pairs, 7 socks must be drawn.
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3. The first 5 balls drawn could be white, so an additional 2 must be drawn to ensure 2 red balls. To be sure of 2 red balls, 7 balls must be drawn.
Question 11= B
Question 13= C
I don't know how to do question 12
Answer:
The first, third and last sequences
Please excuse my dear aunt sally ( parentheses, exponents, multiplication, division, addition, and subtraction )
A: (x + 5i)^2
= (x + 5i)(x + 5i)
= (x)(x) + (x)(5i) + (5i)(x) + (5i)(5i)
= x^2 + 5ix + 5ix + 25i^2
= 25i^2 + 10ix + x^2
B: (x - 5i)^2
= (x + - 5i)(x + - 5i)
= (x)(x) + (x)(- 5i) + (- 5i)(x) + (- 5i)(- 5i)
= x^2 - 5ix - 5ix + 25i^2
= 25i^2 - 10ix + x^2
C: (x - 5i)(x + 5i)
= (x + - 5i)(x + 5i)
= (x)(x) + (x)(5i) + (- 5i)(x) + (- 5i)(5i)
= x^2 + 5ix - 5ix - 25i^2
= 25i^2 + x^2
D: (x + 10i)(x - 15i)
= (x + 10i)(x + - 15i)
= (x)(x) + (x)(- 15i) + (10i)(x) + (10i)(- 15i)
= x^2 - 15ix + 10ix - 150i^2
= - 150i^2 + 5ix + x^2
Hope that helps!!!