147k views
4 votes
How can I Factor 9x2-1

User Druckles
by
6.3k points

2 Answers

5 votes

Answer:

(3x - 1)(3x + 1)

Explanation:

9x² - 1 ← is a difference of squares and factors in general as

a² - b² = (a - b)(a + b)

here 9x² = (3x)² ⇒ a = 3x and 1 = 1² ⇒ b = 1, thus

9x² - 1

= (3x)² - 1²

=(3x - 1)(3x + 1) ← in factored form

User Krisanalfa
by
6.1k points
5 votes

Answer:

17 = 17^1

Explanation:

Factor the following integer:

17

17 is not divisible by 2 since 17 is odd and 2 is even:

17 = 17 (17 is not divisible by 2)

The sum of the digits of 17 is 1 + 7 = 8, which is not divisible by 3. This means 17 is not divisible by 3:

17 = 17 (17 is not divisible by 2 or 3)

The last digit of 17 is not 5 or 0, which means 17 is not divisible by 5:

17 = 17 (17 is not divisible by 2, 3 or 5)

Divide 7 into 17:

| | 2 | (quotient)

7 | 1 | 7 |

- | 1 | 4 |

| | 3 | (remainder)

17 is not divisible by 7:

17 = 17 (17 is not divisible by 2, 3, 5 or 7)

The alternating sum of the digits of 17 is 1 - 7 = -6, which is not divisible by 11. This means 17 is not divisible by 11:

17 = 17 (17 is not divisible by 2, 3, 5, 7 or 11)

Divide 13 into 17:

| | | 1 | (quotient)

1 | 3 | 1 | 7 |

| - | 1 | 3 |

| | | 4 | (remainder)

17 is not divisible by 13:

17 = 17 (17 is not divisible by 2, 3, 5, 7, 11 or 13)

No primes less than 17 divide into it. Therefore 17 is prime:

17 = 17

Since 17 is prime it has an exponent of 1:

Answer: 17 = 17^1

User Sardok
by
6.5k points