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alexdallas
- Master | Next Rank: 500 Posts
- Posts: 108
- Joined: Sun Mar 15, 2009 2:04 pm
x is divisible by 42. Which of the following
numbers is definitely a factor of x2? (Choose
all that apply.)
a) 63 b) 33 c) 36 d) 8
ANSWER:
Answer: a) 63 and c) 36
If x definitely has 2, 3 and 7 as factors, then when we square
x, we know that x2 will have two 2s, two 3s and two 7s as
factors. 63 is 7 × 3 × 3, and 36 is 2 × 2 × 3 × 3. Using the
factor foundation rule, we can guarantee that all numbers that
solely use those factors are factors of x2. Both 63 and 36 use
only prime factors found in x2.
My question is: 8=2X2X2. doesnt 8 include 2X2? why isnt 8 a good answer?
thank you to whomever can help
numbers is definitely a factor of x2? (Choose
all that apply.)
a) 63 b) 33 c) 36 d) 8
ANSWER:
Answer: a) 63 and c) 36
If x definitely has 2, 3 and 7 as factors, then when we square
x, we know that x2 will have two 2s, two 3s and two 7s as
factors. 63 is 7 × 3 × 3, and 36 is 2 × 2 × 3 × 3. Using the
factor foundation rule, we can guarantee that all numbers that
solely use those factors are factors of x2. Both 63 and 36 use
only prime factors found in x2.
My question is: 8=2X2X2. doesnt 8 include 2X2? why isnt 8 a good answer?
thank you to whomever can help
