Who can factor this 3x squared-42x plus 144?

Answer 1

The only way to factor that expression is by using imaginary numbers:

(x + 12i)(x - 12i)

You can test that answer by multiplying the terms back together:

= x2 - 12ix + 12ix - (12i)2

= x2 - (122 × i2)

= x2 - (144 × -1)

= x2 + 144

Answer 2

Start with the prime factorization, 2 x 2 x 2 x 2 x 3 x 3. All of the other factors are in there. Start with 1.

Also...

2

3

4 (2 x 2)

6 (2 x 3)

8 (2 x 2 x 2)

9 (3 x 3)

12 (2 x 2 x 3

Dividing those numbers into 144 gives you the rest.

1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 24, 36, 48, 72, 144

Answer 3

(x + 12)(x - 12)

Answer 4

The prime factors of 144 are 2 and 3.

Answer 5

3(x - 8)(x - 6)

Answer 6

2 x 2 x 2 x 2 x 3 x 3 = 144

Answer 7

(x + 12)(x - 12)