Algebra

[nev7770]

My Grand-Daughter has asked me to help her with her Maths. Can any of you help me please.

(x+2)(x-4) =
(2x+5)(3x-2)=
(3x+4)(2x-5)=
(4x+8)3x-2)=
(3x+2y)(2x+3y)=
(x-4)(2x-6)=
(3x+2)2 =
(3x+4)2 =
(7x+2)2 =
(-5x-7)2 =
(x+y)2 =
(4x-2y)2 =

Many Thanks in Advance

Ned

[Tilly2]

I could help you by giving you the answers but that is not going to do your granddaughter much good. She should be able to do these herself, if it's homework.

[bibblebub]

she won't learn much if you simply give her the answers so explain how the distributive law works

[factor-fiction]

She needs to look it up in maths text book or on whichever online site the school uses. I'm pretty sure they will have MyMaths
Where you have (x+y)2 I assume you mean (x +y)².
That one is x²+y² +2xy

[boxtops]

Nev, does she understand the principles of x and y in algebra? If not, she needs to speak to her teacher - there's no point in our giving you the answers.

[pixie373]

Have they given any values for x and y?

[factor-fiction]

They will have been taught a method for doing these- maybe FOIL (smiley face method) or grid method

[factor-fiction]

There won't be values for x and y, pixie- these are just exercises in multiplying/expanding brackets rather than substitution exercises

[Prudie]

Ask your grand daughter what she does know, she won't have been given homework on multiplying out 2 brackets without some prior examples and method.
Alternatively wait because someone won't be able to help themselves and will give you all the answers. That's not going to help her though is it.

[sherrardk]

In my experience it is best if she goes back and asks her teacher to re-explain it. They seem to keep changing the ways they teach Maths and there is nothing worse than confusing a child with the 'old' method when they are using the 'new' method. Most teachers won't mind spending the extra time to get it sorted out.

[pixie373]

Ok factor. I assume foil is the first-outside-inside-last order of multiplying?

[Psybbo]

Could one of you not give an example of one of them to show how they are done?

[sandyRoe]

Is the 1st one, X squared-2X-8 ?

[factor-fiction]

Okay Psybbo- but it's difficult to present the FOIL method here - far better to look at a maths site
(x +y)²= (x+y)(x+y)= x² + xy + yx+ y²= x² +2 xy + y²

[bibblebub]

ok, in general:-

(ax + b)(cx + d)

= ax(cx + d) + b(cx + d)

= acx² + adx + bcx + dc

= acx² + (ad+bc)x + dc

[bibblebub]

oops, last term should be:- bd

[factor-fiction]

I suggest she looks at these examples and practises some of them
http://www.algebrahelp.com/worksheets/view/simplifying/foilmethod.quiz

[THECORBYLOON]

If you have a look at this site, you can type in the expressions it will show the steps and the solutions, http://m.quickmath.com/#results?c=solve_solveproblem&;v1=(x%2B7)(x-7)&v2=simplify&v7=2

[pixie373]

Factor has done. I don't have the right keys on my phone, but-
for the first one-
multiply the two x's, you have x squared
multiply the outside ones, you get -4x
multiply the inside, you get 2x
multiply the last, you get -8

add them all together-
x2-4x plus 2x-8
simplify it
x2-2x-8. (the x2 is x squared)

[factor-fiction]

Show her this youtube guide. I've not watched it but it seems to cover the method Media URL: http://revisemaths.org.uk/algebra/expanding-double-brackets/
Description:

[Psybbo]

Thanks, I think I understand x