can some1 help with these questions im not getting math ill do anything please help?

Question

Expand each of the following
(x + 3)(x - 2) b) (3x - 7)(x + 4) c) (x - 3)(x + 10)
(x + 5)(x) e) (x + y)(x – 2y) f) (4x + 5)(2x - 3)
Common factor each of the following using the greatest common factor
-3x4y2 - 6x2y5 – 21x5y3 b) 2x3 + 4x3 + 8x9
Factor each of the following
x2 + 5x + 6 b) x2 – 13x – 30 c) x2 + 8x + 12
x2 – 9x + 20 e) x2 – 11x + 18 f) x2 + 7x + 10


if you have msn and get this stuff please add me to explain i have an exam i 2 weeks and im trying to do reviews on my own im not getting it email is [e-mail]

Answer 1

when u have to expand (a+c)(b+d) then u will get
ab + ad + cb + cd

solving a) (x+3)(x-2) = x^2 - 2x + 3x -6 = x^2 + x -6
b) (3x-7)(x+4) = 3x^2 + 5x - 28
c) (x-3)(x+10) = x^2 +7x -30
d) x^2 + 5x
e) x^2 -xy - 2y^2
f) 8x^2 -2x -15

common factor means you have to find something common between all values (like when u r working on fractions) for that you search for the smallest coefficient of x and y to make sure it is in all the values
a) -3x^4y^2 - 6x^2y^5 -21x^5y^3 = -3 x^2y^2 ( x^2 + 2y3 + 7x^3y)
b) 2x^3(3 + 8x^6)

I'm too tired to continue now, maybe i'll do it later lol, but seriously u should ask your teacher u need to understand these, they r very easy, what will u do later????

Answer 2

Steffi, you need a tutor. You can't ask us here in yahoo to do all these exercises that you gave. I'll just do one of each, ok?

Expand: (x+3)(x-2). First multiply x and x=x^2. Then
multiply 3 and x=3x, and -2 and x=-2x. Add them. You
get 3x-2x=x. Then multiply 3 and -2=-6. The three
terms you are looking for will then be:
x^2+x-6.

What did we do? We multiplied (x )(x )=x^2 Then we multiplied ( 3)(x ) =3x, and (x )( -2)=-2x, and added the two products= x. Then we multiplied
( 3)( -2)=-6.

Common factor: Examine the terms. What is common to each? The number 3, x^2, and y^2. So dividing the expression by 3x^2y^2 we get:
3x^2y^2(x^2-2y^3-7x^3y)

Factor each. x^2+5x+6. First write (x )(x ) then
( +3)( +2). Now combine the two:
(x+3)(x+2). If you multiply (x+3) and (x+2) you will get the given expression.

Tutoring can't be done by email, Steffi. We at yahoo can give you some help, but not the same way a tutor
will be able to.

Answer 3

When multipling polynomials, you need to multiply all of the terms in the first polynomial by all of the terms in the second polynomial. Remeber that terms are seperated by + or - signs.
So (x+3)(x-2)
mulitply the x in the first polynomial by all of the terms in the second polynomial. Then multiply the 3 by all of the terms in the second polynomial
(x*x)+(x*-2)+(3*x)+(3*-2)
x^2-2x+3x-6
x^2+x-6

Try the others by yourself, if you can not get them then email me and I will do them for you.

the second expression look for things common in all the terms such as an x and y

xy[(-3*4*2)-(6*2*5)-(21*5*3)]
Now prime factor your numbers
xy[(-3*2^2*2)-(3*2*2*5)-(3*7*5*3)]
collect like terms and arrange in ascending order
xy[(2^3*3)-(2^2*3*5)-(3^2*5*7)]
the only number common to all 3 terms is 3
3xy[(2^3)-(2^2*5)-(3*5*7)]

as for the factoring I will do a couple if you need more help then email me and I'll do it on paper scan it and email it back to you.

x^2+5x+6 can not be factored as it involves imaginary numbers
b) x^2-13x-30
(x-15)(x+2)

Rember a few rules if the last sign is + then the signs are the same in the factors. If the last sign is a - then the signs are different in the factors. Also the numbers are going to be multiples of the last term. In the last case the only options were the factors of 30 is (30*1), (15*2), (3*10), (5*6).

Good luck again if you need more help email me and I will send it to you.

Answer 4

For the expansion remember "FOIL" meaning multiply first the FIRST terms of the brackets, then the Outer terms, then the Inner terms, then the Last terms.
In the first example this would be x*x + x*-2 + 3*x + 3*-2 which simplifies to x^2 + x - 6


A Common Factor is part of the equation/phrase which is a factor of every term.
In the first case, you see that -3x^2 is a common factor, as is y^2
so pull out -3x2y2 and bracket the rest so:
-3x2y2(x2y2 + 2xy3 + 7x3y)


To Factor those expression is the opposite of expanision.
You must get them in the form (x+a)(x+b) such that a*b = the constant and a+b = the x term.
For the first example we can see that 3 and 2 will add together to make 5 and multiply to make 6 so we can factorise as (x+2)(x+3)

Be careful with negative numbers.



And good luck.

Answer 5

These are fundamental. Some one can do this for you on the internet. who will do it for you at your exam in 2 weeks or 12 weeks. What would you do with equations. I'll only tell you that the first factor would have an x to the power of 6 like X*6 where x*6 means x.x.x.x.x.x. Second will also have x*6 but it will also have x*m.y*n where m an have numerical values greater than 1.

Now somebody will give you answers. But that would be cheating. Put your mind to it.