1. -5(3x - 7)
2. -4x2(3x2 - x + 1)
3. -y3(2x2y - 4xy2)
4. 3a3b2(-a3b - a2b2)
5. (x - 4)(x + 8)
6. (2x - 5)(x - 9)
7. (3x + 4)2
8. (5 + x)(3 - 2x)
9. (2x - 3)(x2 + 5x - 3)
10. (2x2 - 5x - 1)(x2 + x - 3)
Help me Please im so lost?
2008-05-15 3:58 pm
回答 (13)
2008-05-15 4:17 pm
✔ 最佳答案
why so ? learn the basic rules.1. -5(3x - 7) = (– 5) × 3x – 7 × (–5)
= – 15x + 35
2. -4x²(3x² - x + 1) similar to above
– 12x^4 + 4x³ – 4x²
3. -y³(2x²y - 4xy²)
= – 2x²y^4 + 4xy^5
4. 3a³b²(-a³b - a²b²)
= – 3a^6b³ – 3a^5b^4
5. (x - 4)(x + 8)
= x (x + 8) - 4(x + 8)
= x² + 8x – 4x – 32
= x² + 4x – 32
6. (2x - 5)(x - 9) similar to above
7. (3x + 4)²
= (3x + 4)(3x + 4) similar to above
8. (5 + x)(3 - 2x) similar to above
9. (2x - 3)(x² + 5x - 3) similar to above
10. (2x² - 5x - 1)(x² + x - 3) similar to above
--------
2008-05-15 11:02 pm
Sorry. Do your own algebra homework. It ain't hard.
2008-05-15 11:17 pm
LOL. You're lazy man.Try to study this.
http://www.intmath.com/Basic-algebra/2_Multiplication-algebra.php
1. -15x+35
2.-12x²²+4x³-4x²
-4x²(3x²-x+1) *²²=4
3.-2x²y²y²+4xy²y²y
2xy²y²(2y-x)
geeez i'm getting lazy too. Just study math.
http://www.intmath.com/Basic-algebra/2_Multiplication-algebra.php
http://www.intmath.com/Basic-algebra/2_Multiplication-algebra.php
1. -15x+35
2.-12x²²+4x³-4x²
-4x²(3x²-x+1) *²²=4
3.-2x²y²y²+4xy²y²y
2xy²y²(2y-x)
geeez i'm getting lazy too. Just study math.
http://www.intmath.com/Basic-algebra/2_Multiplication-algebra.php
2008-05-15 11:15 pm
Multiply everything inside the brackets by the number outside so for number 1:
(-5 x 3x ) + (-5 x -7)
so
-15x + 35
When you have 2 brackets, you take the first number and multiply it by the 2 in the second brackets. If you cant do these, ask your teacher because there is no point in getting the answers unless you understand how.
(-5 x 3x ) + (-5 x -7)
so
-15x + 35
When you have 2 brackets, you take the first number and multiply it by the 2 in the second brackets. If you cant do these, ask your teacher because there is no point in getting the answers unless you understand how.
2008-05-15 11:11 pm
Give a man a fish feed him for a day, teach a man to fish feed him for life...
With the later ones past 4
the method used in these is called f.o.i.l.
First (*-o)(*-0)
Outer (*-0)(0-*)
Inner(0-*)(*-0)
Last(0-*)(*-0)
You take the * on these and multiply them together into a straight line
Once you have this you put them together
Example:
Multiply the following: (6x+1)(2x+9)
Solution:
Just follow the letters in FOIL:
First: 6x*2x=12x2.
Outside: 6x*9=54x.
Inside: 1*2x=2x.
Last: 1*9=9.
Sum it all up and you get: (12x2+56x+9).
With the later ones past 4
the method used in these is called f.o.i.l.
First (*-o)(*-0)
Outer (*-0)(0-*)
Inner(0-*)(*-0)
Last(0-*)(*-0)
You take the * on these and multiply them together into a straight line
Once you have this you put them together
Example:
Multiply the following: (6x+1)(2x+9)
Solution:
Just follow the letters in FOIL:
First: 6x*2x=12x2.
Outside: 6x*9=54x.
Inside: 1*2x=2x.
Last: 1*9=9.
Sum it all up and you get: (12x2+56x+9).
2008-05-15 11:10 pm
Multiply each term in one expression by each term in the other
10. (2x2 - 5x - 1)(x2 + x - 3)
2x^2 - 5x - 1
1x^2 + 1x - 3
- - - - - - - - - - -
2x^4 - 5x^3 - 1x^2
. . . . .+ 2x^3 - 5x^2 - 1x
. . . . . . . . . . .- 6x^2 + 15x + 3
- - - - - - - - - - - - - - - - - - - - - -
2x^4 -3x^3 -12x^2 + 14x + 3
line up like terms in the same column
10. (2x2 - 5x - 1)(x2 + x - 3)
2x^2 - 5x - 1
1x^2 + 1x - 3
- - - - - - - - - - -
2x^4 - 5x^3 - 1x^2
. . . . .+ 2x^3 - 5x^2 - 1x
. . . . . . . . . . .- 6x^2 + 15x + 3
- - - - - - - - - - - - - - - - - - - - - -
2x^4 -3x^3 -12x^2 + 14x + 3
line up like terms in the same column
2008-05-15 11:02 pm
-15x+35 is the first one. Thats all i know, sorry!
2008-05-15 11:22 pm
1)
-5(3x - 7)
= -5*3x + 5*7
= -15x + 35
2)
-4x^2(3x^2 - x + 1)
= -4x^2*3x^2 + 4x^2*x - 4x^2*1
= -12x^4 + 4x^3 - 4x^2
3)
-y^3(2x^2y - 4xy^2)
= -2x^2y^4 + 4xy^5
4)
3a^3b^2(-a^3b - a^2b^2)
= -3a^6b^3 - 3a^5b^4
5)
(x - 4)(x + 8)
= x*x - 4*x + 8*x - 4*8
= x^2 - 4x + 8x - 32
= x^2 + 4x - 32
6)
(2x - 5)(x - 9)
= 2x*x - 5*x - 2x*9 + 5*9
= 2x^2 - 5x - 18x + 45
= 2x^2 - 23x + 45
7)
(3x + 4)^2
= (3x + 4)(3x + 4)
= 3x*3x + 4*3x + 3x*4 + 4*4
= 9x^2 + 12x + 12x + 16
= 9x^2 + 24x + 16
8)
(5 + x)(3 - 2x)
= 15 + 3x - 10x - 2x^2
= -2x^2 - 7x + 15
9)
(2x - 3)(x^2 + 5x - 3)
= 2x^3 - 3x^2 + 10x^2 - 15x - 6x + 9
= 2x^3 + 7x^2 - 21x + 9
10)
(2x^2 - 5x - 1)(x^2 + x - 3)
= 2x^2*x^2 - 5x*x^2 - 1*x^2 + 2x^2*x - 5x*x - 1*x - 2x^2*3 + 5x*3 + 1*3
= 2x^4 - 5x^3 - x^2 + 2x^3 - 5x^2 - x - 6x^2 + 15x + 3
= 2x^4 - 5x^3 + 2x^3 - x^2 - 5x^2 - 6x^2 - x + 15x + 3
= 2x^4 - 3x^3 - 12x^2 + 14x + 3
-5(3x - 7)
= -5*3x + 5*7
= -15x + 35
2)
-4x^2(3x^2 - x + 1)
= -4x^2*3x^2 + 4x^2*x - 4x^2*1
= -12x^4 + 4x^3 - 4x^2
3)
-y^3(2x^2y - 4xy^2)
= -2x^2y^4 + 4xy^5
4)
3a^3b^2(-a^3b - a^2b^2)
= -3a^6b^3 - 3a^5b^4
5)
(x - 4)(x + 8)
= x*x - 4*x + 8*x - 4*8
= x^2 - 4x + 8x - 32
= x^2 + 4x - 32
6)
(2x - 5)(x - 9)
= 2x*x - 5*x - 2x*9 + 5*9
= 2x^2 - 5x - 18x + 45
= 2x^2 - 23x + 45
7)
(3x + 4)^2
= (3x + 4)(3x + 4)
= 3x*3x + 4*3x + 3x*4 + 4*4
= 9x^2 + 12x + 12x + 16
= 9x^2 + 24x + 16
8)
(5 + x)(3 - 2x)
= 15 + 3x - 10x - 2x^2
= -2x^2 - 7x + 15
9)
(2x - 3)(x^2 + 5x - 3)
= 2x^3 - 3x^2 + 10x^2 - 15x - 6x + 9
= 2x^3 + 7x^2 - 21x + 9
10)
(2x^2 - 5x - 1)(x^2 + x - 3)
= 2x^2*x^2 - 5x*x^2 - 1*x^2 + 2x^2*x - 5x*x - 1*x - 2x^2*3 + 5x*3 + 1*3
= 2x^4 - 5x^3 - x^2 + 2x^3 - 5x^2 - x - 6x^2 + 15x + 3
= 2x^4 - 5x^3 + 2x^3 - x^2 - 5x^2 - 6x^2 - x + 15x + 3
= 2x^4 - 3x^3 - 12x^2 + 14x + 3
2008-05-15 11:03 pm
multiply them out. You could have done these in
the time it took to write them.
the time it took to write them.
2008-05-15 11:02 pm
I'm not doing your math homework for you. But, you distribute the numbers through the parenthesis. The problems like #5, do Outside/Inside. Take 8x-4x. Good luck.
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