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13 answers

First: multiply the 1st & 3rd term to get 30. find two numbers that give you 30 when multiplied & (-31) when added/subtracted. the numbers are (-1 & -30). Rewrite the expression with the new middle terms.

x^2 - 1x - 30x + 30

Sec: with 4 terms - group "like" terms & factor both sets of parenthesis.

(x^2 - 1x) - (30x + 30)
x(x - 1) - 30(x - 1)

Third: make sure the inner terms are the same. write the inner term (once) with the outer term.

(x - 1)(x - 30)

2007-05-12 16:41:45 · answer #1 · answered by ♪♥Annie♥♪ 6 · 0 0

x^2-31x+30 since 30>0, both constants will have the same sign.
Since -31<0, both constants will be <0
find 2 factors of 30 that add to 31. They are 1 & 30.
x^2-31x+30=(x-30)(x-1)

2007-05-12 13:50:11 · answer #2 · answered by yupchagee 7 · 0 0

Ok, here's how i would do it

first split the x2 and the 30 in two factors, the first one would be

x and x, because x*x = x2

and the second one would be

-30 and -1 because -30*-1=30

then you place them like this

x -30

x -1
------------

now you make a cross multiplication

x*-30 = -30x and x*-1=-x

and now you add the results

-30x-x = -31x

notice that -31x is the same thing you get in the middle of the expression, this tells you that the factors are correct, now all you have to do is that you add them into a parenthesis and multiply them like this

x + -30
x + -1
---------------
(x-30)*(x-1) and this is your answer (x-30)*(x-1)

now if you want to prove if you are right you just opperate them again like this

x*x + x*-1 + (-30)*x + (-30)*(-1) = x2 -x -30x +30 = x2-31x+30

hope this helps :o)

2007-05-12 12:56:24 · answer #3 · answered by mensajeroscuro 4 · 0 1

x^2-31x+30
first you have to make two sets of parentheses
( )( )
then think of the factors of x and put it in the beginning of each parentheses, so when you foil it, it comes out to be x^2
(x )(x )
now to get the second halves of the parentheses, you have to think of the factors of 30, and make sure the numbers you use can add together to make -31.
(x -30)(x-1)
the signs are both negative because you need to have a negative 31x and a positive 30.

now FOIL the two parentheses, and make sure you have what you had in the beginning: x^2 - 31x + 30
(x-30)(x-1)
x^2 - 1x -30x +30
combine like terms, then:
x^2 - 31x +30

ANSWER: (x-30)(x-1)

2007-05-12 12:59:08 · answer #4 · answered by j93Sapphire 2 · 0 1

You need to find a pair of factors of 30 that add up to 31.

Factors of 30 include:

1, 30
2, 15
3, 10
5, 6

1, 30 are your choice.

Since the sign before 30 is positive, the signs in your factors will be the same (+ times + gives +, - times - gives -). Since the sign in front of 31x is negative, the signs will both be negative.

So, the result is:

(x-1)(x-30)

You can double check by FOIL-ing your answer to see if you get back to where you started.

2007-05-12 12:50:27 · answer #5 · answered by brad p 3 · 0 1

X2-31x+30
(x-30)(x-1)
x=1,30

2007-05-12 12:50:02 · answer #6 · answered by sparkles 6 · 0 1

(x-1)(x-30)

First you have to look at the possible factors of +30, and them together to see if they get -31.
1+30=31
2+15=17
3+10=13
5+6=11
-5-6=-11
-3-10=-13
-2-15=-17
-1-30=-31 <-- that's the one. Just multiply out (x-1)(x-30) to verify that it's x2-31x+30.

2007-05-12 12:49:07 · answer #7 · answered by i♥sf 5 · 0 1

The answer must be of the form (x (+/-) a)(x (+/-) b) where a,b can be real, complex, or imaginary numbers. By inspection we need two numbers whose product is +30 and whose sum is -31.

Try a,b = -1,-30 and multiply the resulting factors into a binomial to verify.

If the coefficient of x^2 is not 1, things get more complicated.

2007-05-12 12:55:04 · answer #8 · answered by Uncle Al 5 · 0 0

factors into (x-30) (x-1) no steps needed

just figure out what 2 numbers make a total of -31 when added and 30 when multiplied.

2007-05-12 12:49:13 · answer #9 · answered by Anonymous · 0 1

You need two numbers that multiply to give 30 and add to give - 31
These numbers are - 30 and - 1 and factors are:-
(x - 30).(x - 1)

2007-05-13 02:58:20 · answer #10 · answered by Como 7 · 0 0

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