Mathematics - 25 September 2007

How do you solve a question like this:
Solve this linear system:
a-b-c=-1
a+c=2
a-2b=-7

I`m used to solving it when there`s 3 of the same variables in each equation...these are mixed up. How do I do this

2007-09-25 17:12:45 · 6 answers · asked by Laney 2

2007-09-25 17:10:42 · 6 answers · asked by ohoma 1

strontium-90 has a half life od 25 years. how much time has elapsed if the following fraction remains in a sample?
1) 1/4
2) 1/32

2007-09-25 17:06:42 · 5 answers · asked by Anonymous

1. Evaluate 8x - 4y when x=2 and y=3

2. Simplify 3 - 10 + 9 x 7

3. Simplify 16 - 10 divided by 5 + 10

4 Simplify 2 + 3 x 10 divided by 5 x 3 - 9

5. Evaluate 3x + 5y when x=11 and y=4

2007-09-25 16:57:01 · 5 answers · asked by quaqua88 1

I have the answers to this problems because they're in the back of my book, but can somebody explain me how to do them? They are simple but I dont know any math. :(

14 is 30% of what numer?

what is 2% of 40?

sammy sosa had 193 hits, his batting average was 0.320 (32%) this is the total of at-bats (32%) how many at-bats did he have?

2007-09-25 16:54:48 · 15 answers · asked by JESSY JAY! 3

Slope-intercept form of 4x = -1/2y - 1?

2007-09-25 16:50:35 · 3 answers · asked by ShaZ 1

y= 6x / (x+1)^2 at point (0,0)

2007-09-25 16:40:47 · 2 answers · asked by Anonymous

f(x) =(x-1/x-5)

g(x)= -(5x+1\x-1)

2007-09-25 16:40:04 · 5 answers · asked by Sam Dali 2

math

2007-09-25 16:36:30 · 7 answers · asked by stacy h 1

ok... not a clue!! someone please help... i got... 6x^2+8x-7 , but where do i go from here??

2007-09-25 16:32:48 · 3 answers · asked by Anonymous

2007-09-25 16:27:51 · 1 answers · asked by birmingham927 2

simpson drives his car with an average velocity of 48.2km/h to the east.
How much time would simpson save by incrasing his average velocity to 68.8km/h to the east? answer in min.
Explain answer...

2007-09-25 16:27:31 · 1 answers · asked by kf4carlo 1

y = ( x^2 + 9 ) / ( 9x^2 - 35x - 4 )

x =______
x =______
y =______

y = ( 2e^x ) / ( e^x - 7 )

x = ____
y = ____

2007-09-25 16:24:26 · 1 answers · asked by ABC911 1

Let S denote the infinite sum 2 + 5x + 9x^2 + 14x^3 + 20x^4 + ...., where |x| < 1 and the coefficient of x^(n-1) is ½ n (n + 3), (n = 1, 2, ....). Then S equals ?

can anybody tell,how to solve this kind of problem ?

my book has given a procedure to do s-x*s

why shall i do that ? does the problem tells any ideas to go about ?

someone please explain

2007-09-25 16:22:06 · 1 answers · asked by calculus 1

Use the Distributive Property to write each expression as an equivalent algebraic expression.

-6(t-1)

-12(g+12)

13(p+4)

Simplify each expression.

6y-a+y



By the way, these are just so I can check to see if I'm doing them right!

2007-09-25 16:20:44 · 8 answers · asked by Anonymous

f(t) = t -1 - t

2007-09-25 16:20:16 · 1 answers · asked by Anonymous

It's been a while, and when we did this I didn't even fully grasp it (I'm more of an english and history person than a math and science one) and it's on a review sheet I need to get done. Among other things. PLEASE HELP ME!!!!

2007-09-25 16:19:34 · 9 answers · asked by Sarah 1

i am in algebra and i have to classify numbers like -5 ,2 ,5/2
64 squared etc. i have to classify them as real,rational,irrational,integer,and whole numbers i dont understand how you know which number is which.

2007-09-25 16:13:19 · 3 answers · asked by Anonymous

solve this equation 40a^2 + 4a = 0 if possible can you show the steps

2007-09-25 15:57:57 · 5 answers · asked by Riddle 1

2007-09-25 15:53:52 · 3 answers · asked by Aquabug222 1

Write an expression for each phrase:

Ten times the result of eleven minus two:



The quanitity P minus five eighths time the result of one fourth plus P:

2007-09-25 15:53:18 · 4 answers · asked by Anonymous

so i need the answer to this:

Determine the limit of the function describing the atmospheric pressure on a plane as it descends from 32,000 feet to land at Honolulu, located at sea level. (The atmospheric pressure at sea level is 14.7 lb/in^2).

Dang I hate calculus this is only chapter 1! please give the answer as a limit and show work that you use. THANKS

2007-09-25 15:50:25 · 2 answers · asked by -N- 2

1) Nicole gets paid $8.25 an hour. She worked 8 hours on Friday. How much did she earn that day?

a. $52.00
b. $59.75
c. $66.00
d. $70.50
_______________________
2) what is the value of this expression?

3(15+9) - 2 x 11 = ?

a. 30
b. 50
c. 572
d. 770

______________
3) Sydney bought 5 new notebooks for $1.35 each and 12 pens that cost 3 for 1.25. What is the total amount she spent, not including Tax, on notebooks and pens?

a. $8.00
b. $10.50
c. $11.35
d. $11.75

________
its cuz i dont really remember when they teached these problems and i dont remember them =[ please help its home work and its due tommorow.

2007-09-25 15:45:55 · 9 answers · asked by Anonymous

Consider the elements
| 0 -1| = A
| 1 0 |
and

| 0 1 | = B
| -1 -1|

from SL(2, R). How do you find |A|, |B|, and |AB|.
Is this answer surprising?

(A and B are 2x2 matrices)

2007-09-25 15:37:20 · 2 answers · asked by Anonymous

3 consecutive even integers are given by x, x+2, and x+4
Find these three numbers such that the sum of the first, two times the second, and three times the third is 124. pliss someone explain how you get to ya answer

2007-09-25 15:32:48 · 8 answers · asked by petite fille 2

ok so i need help with these answers so i can explain them to my cousin with his homework i need answers and explaining...:)


solve for x
1. 2p=kx-q

2.e=rx

solve for y
1.ry+s=ts-m

2.2/3y+k=j

3.2/3y+a=a+b

2007-09-25 15:11:44 · 7 answers · asked by needs advice 1

int (2, infinity) 1dx/(x+3)^(3/2)

2007-09-25 15:07:59 · 3 answers · asked by Anonymous

how do i find the zeroes of this function.
f(x) = x^3 - 2x^2 - 4x

How do I solve this

2007-09-25 15:07:11 · 3 answers · asked by Big Bob 2

I feel pretty stupid, this one stumped me and my husband. There is a pic of a dog, Duke. The scale factor from Duke to the drawing is 12-1/2%. He needs to figure how long and how tall Duke is. Then the last question is what setting would you put a copier on, 50 to 200%, to make a life size poster of Duke. I am not quite sure how to help him on this one. Please Help!!

2007-09-25 15:04:35 · 6 answers · asked by umbarger 2

2007-09-25 14:56:54 · 4 answers · asked by Trigo L 1