2007-04-22 06:51:33 · 6 answers · asked by Helper 1 in Science & Mathematics ➔ Mathematics
(2x-9)(x-2)
First you need to find factors for 2x^2, there is only one pair and that is 2x and x.
Then you need to find factors of 18, that includes 2 and 9, also 3 and 6.
When you see there is a negative sign in front of your second number -13x and a positive number in front of your third number +18, you know that the both of the other factors have to be negative.
Next you try out different combinations such as what's 2 times -6 plus 1 times -3, that equals 15, it's wrong because it doesn't give you 13.
After a few trial and error you should find 2 times -2 plus 1 times -9 gives you -13.
In the end you put -9 in the first parenthesis and -2 in the second parenthesis. Because you cross multiply them.
If you need explanation please tell me.
2007-04-22 06:55:47 · answer #1 · answered by Your Future Doctor 2 · 0⤊ 0⤋
2x^2-13x+18
=2x^2-4x-9x+18
=2x(x-2)-9(x-2)
=(2x-9)*(x-2)
AND THIS IS A BEST ANSWER SO RATE IT BEST!!!
2007-04-22 06:54:59 · answer #2 · answered by SuNiL 3 · 0⤊ 0⤋
All of their answers are right. It is
(2x-9) (x-2)
My 8th grade teacher taught us a method called the tic-tac-toe method. Draw a tic-tac-toe borard Number your boxes 1-9 like this and follow my explanation for each box.
1 2 3
4 5 6
7 8 9
1. put the first term in this box. (2x^2)
2. put the last term in this box. (18)
3. multiply the numbers in boxes 1 and 2 and put it in box 3.
(36x^2)
6. and 9. Find two numbers that when you add them, they equal the number in the second term and when you multiply them, it equals the number in the third box.
(-9x X -4x= 36x^2)
(-9x+-4x= -13x)
Once you find them put them in boxes 6 and 9 in any order
(-9x and -4x)
7. Find the GCF of boxes 1 and 9 and put it in box 7.
Remember, the GCF is never negative. (the GCF of 2x^2 and -4x is 2x)
4. ask yourself "what do you multiply box 7 by to get box 1?"
(what do you multiply 2x by to get 2x^2 ?)
(x)
8. ask yourself "what do you multiply box 7 by to get box 9?"
(what do you multiply 2x by to get -4x ?)
(-2)
9. ask yourself "what do you multiply box 4 by to get box 6?"
(what do you multiply x by to get -9x ?)
(-9)
Review:
1. 2x^2
2. 18
3. 36x^2
4. x
5. -9
6. -9x
7. 2x
8. -2
9. -4x
Put boxes 7 and 5 in parenthesis
Put Boxes 4 and 8 in parenthesis
you have your answer
2007-04-22 07:32:37 · answer #3 · answered by Purrisha 1 · 0⤊ 0⤋
by general quadratic factoring..
we have..
(2x - 9)(x - 2)
2007-04-22 06:55:50 · answer #4 · answered by cutting_edge 3 · 0⤊ 1⤋
(2x - 9).(x - 2)
2007-04-22 06:56:22 · answer #5 · answered by Como 7 · 0⤊ 0⤋
i realy dont know maybe 62
2007-04-22 07:16:55 · answer #6 · answered by Anonymous · 0⤊ 0⤋