In Algebra. I don't understand FOIL can you please help me figure these problems?

1) -15x+35

2) -12x^4+4x^3-4x^2

3) -2xy^4+4xy^5

4) -3a^6b^3-3a^5b^4

5) x^2+4x-32

6) 2x^2-23x+45

7) 9x^2+24x+16

8) -2x^2-13x+15

9) 2x^3+7x^2-21x+9

10) 2x^4-3x^3-22x^2+14x+3

FOIL means First, Outer, Inner, Last.

What that means for 5, 6, 7, 8, 9 is you do the multiply the first set in each parentheses. Then multiply the outer set and either add/subtract depending on the equation, then multiply the inner and add/subtract, then you multiply the last set of each parentheses.

I'll do the first one for you.

5. (x - 4)(x + 8)

F = (multiply first set which is x * x) = x²

O = (mutlipy the outter set which is +8 * x) = 8x

I = (multiply the inner set which is -4 * x) = -4x

L = (multiply the last of each set which is +8 * -4) = -32

x² + 8x - 4x - 32 (

Answer = x² + 4x - 32

try the others on your own ... Just have to take your time on them.

First of all, you need to distinguish between coefficients and exponents. On the keyboard, you can represent an exponent by using the caret ^ (above the 6). You would write x-squared as

x^2

So, you should probably re-enter your problems using the correct expressions for exponents.

You should also review the concept of distribution.

Try reading your textbook. If you are truly having problems with understanding FOIL, then you should go to your teacher for help. This is pretty easy material. If you don't understand this, you will not be able to go forward in algebra.

Good luck.

FOIL stands for First, Outer, Inner, Last. It is the order in which you multiply out double brackets.

eg

(x+a)(x-b)

-->x*x (first)

x*-b (times by outer)

a*x (outer)

a*-b (last)

Piece this all together and you get

X^2 -bx +ax -ab

1) -5*3x + -5*-7 (remember double negative multiplication goes to positive)

-->-15x + 35

2) I assume you mean -4x^2??

If we assume this then -4x^2(3x^2 - x + 1)

--> -4x^2 * 3x^2 + -4x^2* -x + -4x^2 *1

--> -12x^4 (adding of indice powers when multiplying) +4x^3 (double negative -*- =+ and adding of indice powers) -4x^2 *1

--> -12x^4 +4x^3 -4x^2

3 and 4 use similar approach, just remember double negative and adding indices when multiplying

5 and 6) use foil concept at beginning

7) do (3x+4)(3x+4) then same as above

8) same as 5,6,7 just remember the double negatives (x*-2x = -2x^2)

9) Use foil principles. Multiple 2x by everything in right hand side bracket, then multiply -3 by everything in right hand side bracket. Add all this together.

10) Multiple 2x^2 by everything in right hand side bracket. Then multiple -5x by everything in right hand side bracket. Finally multiply everything in right hand bracket by -1. After you get all these terms, shoud be 9 in total ranging from 2x^4 to positve 3. Add them all together, paying carefull attention to double negatives.

Hope this helps.

if x^2 it means x to the 2nd power

1. -15x +35

2. -12x^4 + 4x^3 - 4x^2

3. -2x^2y^4 + 4xy^5

4. -3a^6b^3 - 3a^5b^4

5. x^2 + 4x - 32

6. 2x^2 - 23x + 18

7. 9x^2 + 24x + 16

8. 15 - 7x - 2x^2

9. -3x^2 + 12x^2 - 21x + 9

10. 2x^4 - 3x^3 - 12x^2 + 16x + 3

FOIL:

FIRST - multiply the first numbers of each bracket together

OUITSIDE- multiply the first number of the first bracket, then the second number of the second bracket

INSIDE- the second number of the first bracket, then first number of the second bracket

LAST- second numbers of each brackets

example

8. (5 + x)(3 - 2x)

FIRST:

5 x 3

OUTSIDE:

5x x (-2x)

INSIDE:

x x 3

LAST:

x x (-2x)

so your final equation is

15 - 10x^2 +3x -2x^2 =0

solve for x

hope it helps

You've been taught to distribute right?

That's all it is.

An easier way to look at it would be "tiles":

this is #7:

....3x + 4

3x[9x][12x]

+4[12x][16]

The tiles work diagonally

so your answer would be: 9x+24x+16

Here's #9

.......x2 + 5x - 3

2x [2x3][10x2][-6x]

-3 [-3x2][-15x][9]

Answer:

2x3+7x2-21x+9

questions about anything?

1. -15x + 35

2. -12x^4 + 4x^3 - 4x^2

3. -2xy^4 + 4xy^5

4. -3a^6b^3 - 3a^5b^4

5. x*x + 8x - 4x - 8*4 =

.....x^2 + 4x - 32

6. 2x*x - 2x*9 - 5x + 9*5 =

.....2x^2 - 18x - 5x - 32 =

.....2x^2 - 23x - 32

7. 3x*3x - 4*3x - 4*3x + 4*4 =

......9x^2 - 12x - 12x + 16 =

......9x^2 - 24x + 16

8. 15 - 10x + 3x - 2x^2 =

......15 - 7x - 2x^2

9. 2x*x^2 + 2x*5x - 2x*3 - 3*x^2 - 3*5x - 3*-3 =

.....2x^3 + 10x^2 - 6x - 3x^2 - 15x + 9 =

.....2x^3 + 7x^2 - 21x + 9

10. 2x^3 + 10x^2 - 6x - 3x^2 - 15x - x^2 - x + 3 =

.....2x^3 + 6x^2 - 22x + 3

Hi penny sorry i dont know the answer to the above question

but you just answered my question

with the alco what do you reccomend and do i wash it off ,leave it on??

thanks

where is the shaded region? is it btween the big and small circle???? to work that out the shaded region= the area odf the big circle- the area of the little circle its like punch out, removing the little cirlce and seeign whats left if the area of the big cirlce is pi* R^2 the area of the littel circles is pi*(R-3)^2 = pi (R^2 - 6R +9) so shaded region area = pi* R^2-pi*(R^2 - 6R +9) =pi(9-6R)