math review? PLEASE help....i forgot how to a few things.....?

Question

ok, so we're doing this review thing in math. i KNOW i learned these a few years ago, but i cant remember how (it starts to slip after around 3 years). can anybody help? ...please? (i did the other 57 so....please?)

1. (x+2)(x+2)
2. (x+3)(x-4)
3. (x-4)(x+4)

isnt it weird how the easiest things slip your mind?

Answer 1

1. (x+2)(x+2) = x^2 + 2x + 2x +4 = x^2 + 4x + 4
2. (x+3)(x-4) = x^2 - 4x + 3x -12 = x^2 - x -12
3. (x-4)(x+4) = x^2 + 4x - 4x - 16 = x^2 -16

Good luck!

=)

Answer 2

The other 57 were functions like this, and you don't remember how to do these last three?

Like you said, the easiest things do slip your mind, so here we go:

Think of these three problems as (A + B) (C + D)

Remember FOIL (first, outside, inside, last) and thanks for the problem because last time this DID slip my mind!

AC + AD + BC + BD

So problem 1 would be:

x^2 + 4x + 4

Problem 2:

x^2 - x - 12

Problem 3:

x^2 - 16 (because 4x - 4x = 0)

Answer 3

in order to do these questions you have to remember the simple formulae like 1) (x+a)^2=x^2+a^2+2xa
2)(x+a)(x+b)=x(x+b)+a(x+b)
3)(x+a)(x-a)=x^2-a^2
the first and the third formulae have been derived from the second.So, the second formula is the ultimate one.Now the answers are:
1)x^2+4+4x
2)x(x-4)+3(x-4)=x^2-4x+3x-12=x^2-x-12
3)x^2-16

Answer 4

(x+2)(x+2) = x(x+2)+2(x+2) = x^2+x2+2x+4 = x^2+4x+4
(x+3)(x-4) = x(x-4)+3(x-4) = x^2+x(-4)+3x-12 = x^2-x-12
(x-4)(x+4) = x(x+4)-4(x+4) = x^2+x4-4x-16 = x^2-16

Answer 5

the general formula is

(a + b)(c + d) = ac + ad + bc + bd.

a special case is

(a + b)(a + c) = a^2 + (c+b)*a + bc

ie

2. (x+3)(x-4) = x^2 + (3-4)x + (3)(-4) = x^2 -x -12

Answer 6

1. x^2 + 4x + 4
2. x^2 - x - 12
3. X^2 - 16

Answer 7

Distribution rule (a.k.a. FOIL, being First term, Outside term, inside term, last term)

x^2 + 2x + 2x + 4 for the first problem. to get: x^2 + 4x +4

I will leave you to do the rest.