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mathxyz

Member

From: Brooklyn, NY

Registered: 2024-02-24

Posts: 1,053

Factor Completely

Factor Completely.

Problem 104; page 58.

9x^2- 24x + 16

I think factor by grouping works here.

Yes?

Bob

Administrator

Registered: 2010-06-20

Posts: 10,627

Re: Factor Completely

I would expect 4 terms for that.

3^2 = 9     4^2 = 16  2x3x4 = 24,

Try a direct factorisation with two identical factors.

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

mathxyz

Member

From: Brooklyn, NY

Registered: 2024-02-24

Posts: 1,053

Re: Factor Completely

I would expect 4 terms for that.

3^2 = 9     4^2 = 16  2x3x4 = 24,

Try a direct factorisation with two identical factors.

Bob

Four terms? It is a quadratic trinomial.

mathxyz

Member

From: Brooklyn, NY

Registered: 2024-02-24

Posts: 1,053

Re: Factor Completely

I would expect 4 terms for that.

3^2 = 9     4^2 = 16  2x3x4 = 24,

Try a direct factorisation with two identical factors.

Bob

9x^2 - 24x + 16

Factor by grouping.

9(16) = 144

(-12)(-12) = 144 but when added equals -24.

9x^2 -12x - 12x + 16

Group A = 9x^2 - 12x

Group B = -12x + 16

Factor each group separately.

Group A

9x^2 - 12x

GCF = 3x

3x(3x - 4)

Group B

-12x + 16

GCF = -4

-4(3x - 4)

I now have this:

3x(3x - 4) - 4(3x - 4)

My answer is (3x - 4)(3x - 4).

Yes?

Bob

Administrator

Registered: 2010-06-20

Posts: 10,627

Re: Factor Completely

Correct.

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

mathxyz

Member

From: Brooklyn, NY

Registered: 2024-02-24

Posts: 1,053

Re: Factor Completely

Correct.

Bob

Thanks but I over did it here with so many postings. I need to be more considerate. I need you to know that starting today, less problems will be posted and only if I get stuck.