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Question 32044: I need help but not sure if I had picked the right topic for this. Here are the problems and all have to be factor completely evidently.
1.x^3-26x^2+48x
2.x^2-6wy+3xy-2wx
3.x^2-5x-14
4.4x^2-36y^2
5.3x^2-2x-8
6.24x^2+10x-4
I am really sorry for putting 6 of these on here but I just do not understand algebra at all. I will appreciate all the help that I can get. Thank you!!!
Answer by AnlytcPhil(1806) (Show Source):
You can put this solution on YOUR website! 1. 1x3 - 26x2 + 48x
Take out x
x(1x2 - 26x + 48)
Multiply the +48 times the 1 before the x2, getting +48
I. Think of two numbers which
A) multiply to give +48
and which also
B) combine to give -26
It doesn't take long to think of -2 and -24 because
A) -2 TIMES -24 gives +48
and
B) -2 PLUS -24 gives -26
II. Write -26x using -2 and -24
-26x = -2x - 24x
III. Replace -26x in
x(x2 - 26x + 48)
with -2x - 24x
x(x2 - 2x - 24x + 48)
IV. Change the parentheses to brackets:
x[x2 - 2x - 24x + 48]
V. Factor out x in the first two terms in the brackets
x[x(x - 2) - 24x + 48]
VI. Factor out -24 in the last two terms in the brackets
x[x(x - 2) - 24(x - 2)]
VII. Factor out the common factor (x - 2) within the brackets
x[(x - 2)(x - 24)]
VIII. Erase the brackets:
x(x - 2)(x - 24)
------------------------------------
2. x2 - 6wy + 3xy - 2wx
I. We can't factor the first two terms, so we must rearrange terms
x2 + 3xy - 2wx - 6wy
II. Factor x out of the first two terms
x(x + 3y) - 2wx - 6wy
III. Factor -2w out of the last two terms
x(x + 3y) - 2w(x + 3y)
IV. Factor out common factor (x + 3y)
(x + 3y)(x - 2w)
-----------------------------
3. 1x2 - 5x - 14
Multiply the -14 times the 1 before the x2, getting -14
I. Think of two numbers which
A) multiply to give -14
and which also
B) combine to give -5
It doesn't take long to think of -7 and +2 because
A) -7 TIMES +2 gives -14
and
B) -7 PLUS +2 gives -5
II. Write -5x using -7 and +2
-5x = -7x + 2x
III. Replace -5x in
x2 - 5x - 14
with -7x + 2x
x2 - 7x + 2x - 14
IV. Factor x out of the first two terms:
x(x - 7) + 2x - 14
V. Factor +2 out of the last two terms:
x(x - 7) + 2(x - 7)
VI. Factor out common factor (x - 7)
(x - 7)(x + 2)
------------------------
4. 4x2 - 36y2
First factor out 4
4(x2 - 9y2)
Change parentheses to brackets and write each as a perfect square
4[(x)2 - (3y)2]
This is the difference of two perfect squares
Learn formula: A2 - B2 factors as (A - B)(A + B)
4[(x) - (3y)][(x) + (3y)]
Remover the inner parentheses
4[x - 3y][x + 3y]
Change brackets to parentheses
4(x - 3y)(x + 3y)
-------------------------------
5. 3x2 - 2x - 8
Multiply the -8 times the 3 before the x2, getting -24
I. Think of two numbers which
A) multiply to give -24
and which also
B) combine to give -2
It doesn't take long to think of -6 and +4 because
A) -6 TIMES +4 gives -24
and
B) -6 PLUS +4 gives -2
II. Write -2x using -6 and +4
-2x = -6x + 4x
III. Replace -2x in
3x2 - 2x - 8
with -6x + 4x
3x2 - 6x + 4x - 8
IV. Factor 3x out of the first two terms:
3x(x - 2) + 4x - 8
V. Factor +4 out of the last two terms:
3x(x - 2) + 4(x - 2)
VI. Factor out common factor (x - 2)
(x - 2)(3x + 4)
----------------------------
6. 24x2 + 10x - 4
Take out 2
2(12x2 + 5x - 2)
Multiply the -2 times the 12 before the x2, getting -24
I. Think of two numbers which
A) multiply to give -24
and which also
B) combine to give +5
It doesn't take long to think of +8 and -3 because
A) +8 TIMES -3 gives -24
and
B) +8 PLUS -3 gives +5
II. Write +5x using +8 and -3
+5x = +8x - 3x
III. Replace +5x in
2(12x2 + 5x - 2)
with +8x - 3x
2(12x2 + 8x - 3x - 2)
IV. Change the parentheses to brackets:
2(12x2 + 8x - 3x - 2)
V. Factor out 4x in the first two terms in the brackets
2[4x(3x + 2) - 3x - 2]
VI. Factor out -1 in the last two terms in the brackets
2[4x(3x + 2) - 1(3x + 2)]
VII. Factor out the common factor (3x + 2) within the brackets
2[(3x + 2)(4x - 1)]
VIII. Erase the brackets:
2(3x + 2)(4x - 1)
Edwin
AnlytcPhil@aol.com
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