Three times the sum of a number and 3 is 3 less than the number times 5. Find the number.
1 answer:
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Natalie is an expert archer. The following table shows her scores (points) based on the number of targets she hit.
Targets hit 111 222 555
Points 333 666 151515
Plot the ordered pairs from the table.
Are Natalie's points proportional to the number of targets she hit?
Choose 1 answer:
(Choice A)
A
Yes
(Choice B)
B
No
Answer: (3b + 5)(3b - 5)
Because both terms, 9b² and 25, are perfect squares, you can factor by taking the square roots of both terms.
The square root of 9b² is 3b (3b × 3b = 9b²).
The square root of 25 is 5 (5 × 5 = 25).
9b² - 25 has a negative, so the factored expression would be
(3b + 5)(3b - 5). The signs (+ and -) alternate in this case because the expression, 9b² - 25, has no middle term.
You can check your work by using FOIL. See the attachment below.
F irst
O utside
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