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Polynomials-and-rational-expressions/186809: There is a sales tax of $12 on an item that costs $147 before tax. A second item costs $134.75 before tax. What is the sales tax on the second item?
1 solutions

Answer 140035 by josmiceli(9698) About Me  on 2009-03-15 19:28:13 (Show Source):
You can put this solution on YOUR website!
What is needed is the rate at which items are taxed
tax/before tax price = rate
12%2F147+=+.08163
.08163%2A134.75+=+11
The tax is $11


Square-cubic-other-roots/186788: Ok I got another question; why doesnt sqrt(5)+1 over sqrt(5)-1= 2+sqrt(5) over 2??
1 solutions

Answer 140012 by josmiceli(9698) About Me  on 2009-03-15 15:48:51 (Show Source):
You can put this solution on YOUR website!
Your answer is close
%28sqrt%285%29+%2B+1%29+%2F+%28sqrt%285%29+-+1%29
Multiply top and bottom by sqrt%285%29+%2B+1

%285+%2B+2%2Asqrt%285%29+%2B+1%29+%2F+4
%286+%2B+2%2Asqrt%285%29%29+%2F+4
%283+%2B+sqrt%285%29%29+%2F+2 answer
You can check the answer by setting
it equal to the original expression
and do the algebra to see if it's true


Sequences-and-series/186780: Deanna received an e-mail asking her to forward it to 10 other people. Assume that no one breaks the chain and that there are no duplicate recipients. How many e-mails will have been sent after 8 generations, including Deanna's?
Could you do this problem? Thank you for your help.
1 solutions

Answer 140003 by josmiceli(9698) About Me  on 2009-03-15 15:16:14 (Show Source):
You can put this solution on YOUR website!
The problem says that the 1st generation of
e-mail senders is Deanna, who receives one
sends emails to 10 other people
So far I have:
generation# --- emails sent
--- 1 --------------1
--- 2 --------------10
So far, 11 people have gotten emails
Now each of the 10 people send 10 emails
and 10%2A10+=+100
So far I have:
generation# --- emails sent
--- 1 --------------1
--- 2 --------------10
--- 3 --------------100
So far 111 people have gotten emails
Now, there are 100 people who are going to send
emails to 10 other people.
100%2A10+=+1000
So far I have:
generation# --- emails sent
--- 1 --------------1
--- 2 --------------10
--- 3 --------------100
--- 4 --------------1000
So far, 1111 people have gotten emails
If I carry this process to 8 generations, the 8th is:
generation# --- emails sent
--- 8 --------------10000000
and the total number of people who have gotten emails is
11,111,111


Equations/186634: This question is from textbook mathematical analysis
a new television depreciates $120 per year, and it is worth $340 after four years. find a function that describes the value of this television, if x is the age of the television in years.
In full details please, thank you
1 solutions

Answer 139924 by josmiceli(9698) About Me  on 2009-03-14 17:30:55 (Show Source):
You can put this solution on YOUR website!
Let y = the original value of the TV
given:
120 = depreciation/1 year
You have to understand that depreciation
is what the TV loses in value each year,
so every year it's worth less, and then it
gets depreciated again
------------------------------------------
y+-+120 is the value of the TV after 1 year
y+-+120+-+120 is the value of the TV after 2 years
y+-+120+-+120+-+120 is the value of the TV after 3 years
y+-+4%2A120 is the value of the TV after 4 years
The problem says the TV is worth $340 after 4 years, so
y+-+4%2A120+=+340
y+=+340+%2B+480
y+=+820
So, the TV was originally worth $820
------------------------------------
Now I need to write a function that tells me the
value of the TV for any given year
If x is the year after purchase,
and V%28x%29 is the value of the TV that year
V%28x%29+=+820+-+120x
A quick check is:
What is the TV worth after 4 years?
V%28x%29+=+820+-+120x
V%284%29+=+820+-+480
V%284%29+=+340
That's what it should be


Distributive-associative-commutative-properties/186662: This question is from textbook Algebra 1
I need help understanding how to find the greatest common factor and factoring it out of a equation.
e.x. 6y^4 + 14y^3 - 10y^2
1 solutions

Answer 139923 by josmiceli(9698) About Me  on 2009-03-14 17:07:48 (Show Source):
You can put this solution on YOUR website!
The limitation on picking out a common factor
is lowest power of a symbol (x,y z, etc), or
it must be the greatest common divisor of
the numbers that are common to each term
6y%5E4+%2B+14y%5E3+-+10y%5E2
The common symbols are:
y%5E4, y%5E3, and y%5E2
The lowest power is 2, so I can
factor out y%5E2
y%5E2%2A%286y%5E2+%2B+14y+-+10%29
For the numbers, the greatest common divisor is 2
so I can factor out a 2
2y%5E2%2A%283y%5E2+%2B+7y+-+5%29


Geometry_Word_Problems/186614: How many different triangles can have sides of length 8 and 11 if the third side must have a length which is an integer?
1 solutions

Answer 139888 by josmiceli(9698) About Me  on 2009-03-14 07:47:37 (Show Source):
You can put this solution on YOUR website!
If I lay the 11 side down flat, I see that sides
equal to 8 and 3 will add up to the 11
side, and will not be a triangle, So I must go higher than 3
for the 3rd side
I can have:
8 and 4
8 and 5
8 and 6
8+ and 8 (this is isosceles)
8 and 9
8 and 10
.
.
.
8 and 18
The next one, 8 and 19 is like the
8 and 3, because it lays down flat
on top of the 11 side, because 19+-+8+=+11
so, the possible integer sides for the 3rd side are:
4 through 18.


Equations/186625: This question is from textbook mathematical analysis
passing through (-7,-5) and parallel to the line 3x+3y+6=0
please with full steps, thank you
1 solutions

Answer 139886 by josmiceli(9698) About Me  on 2009-03-14 07:32:34 (Show Source):
You can put this solution on YOUR website!
First, I'll find the slope of
3x+%2B+3y+%2B+6+=+0
3y+=+-3x+-+6
y+=+-x+-+2
This is in the form y+=+mx+%2B+b
where m= slope, and
m+=+-1
Any line parallel to this one will
also have m+=+-1
The point-slope formula is
%28y+-+y%5B1%5D%29%2F%28x+-+x%5B1%5D%29+=+m
I'm given (-7,-5), so
x%5B1%5D+=+-7
y%5B1%5D+=+-5
m+=+-1
%28y+-+%28-5%29%29%2F%28x+-+%28-7%29%29+=+-1
%28y+%2B+5%29%2F%28x+%2B+7%29+=+-1
Multiply both sides by x+%2B+7
y+%2B+5+=+-x+-+7
Add x+%2B+7 to both sides
x+%2B+y+%2B+12+=+0 answer
check answer
Does it go through (-7,-5)?
-7+-+5+%2B+12+=+0
-12+%2B+12+=+0
OK


Age_Word_Problems/186598: This question is from textbook Algebra Structure and Method Book I
A man is three times as old as his son was at the time when the father was twice as old as the son will be in two years from now. Find the present age of each person if the sum of their ages is fifty-five years.
1 solutions

Answer 139880 by josmiceli(9698) About Me  on 2009-03-14 00:27:19 (Show Source):
You can put this solution on YOUR website!
Let f = Father's age now
Let s = Son's age now
given:
f+%2B+s+=+55
The Son's age in 2 years is
s+%2B+2
When the Father was twice as old as the Son will be in two years is
2%2A%28s+%2B+2%29
How old was the Son then?
The difference in their ages is a constant
f+-+s+=+c
s+=+f+-+c
2%2A%28s+%2B+2%29+-+c
2s+%2B+4+-+c
The Father's present age is three time the Son's at that time
f+=+3%2A2%2A%28s+%2B+2%29+-+3c
(1) f+=+6s+%2B+12+-+3c
also,
(2) f+%2B+s+=+55
(3) f+-+s+=+c
Substitute (3) in (1)
(1) f+=+6s+%2B+12+-+3%2A%28f+-+s%29
(1) f+=+6s+%2B+12+-+3f+%2B+3s
(1) 4f+-+9s+=+12
Multiply both sides of (2) by 4 and
subtract (1) from (2)
(2) 4f+%2B+4s+=+220
(1) -4f+%2B+9s+=+-12
(3) 13s+=+208
(3) s+=+16
and, since
(2) f+%2B+s+=+55
(2) f+=+55+-+16
(2) f+=+39
The father is 39 now, and the Son is 16
----------------------------------------
check answer:
The Son's age in 2 years is
16+%2B+2+=+18
When the Father was twice as old as the Son will be in two years is
2%2A%2816+%2B+2%29
36
How old was the Son then?
The difference in their ages is a constant
36+-+s+=+c
s+=+36+-+c
2%2A%28s+%2B+2%29+-+c
2s+%2B+4+-+c
The Father's present age is three time the Son's at that time
39+=+3%2A2%2A%28s+%2B+2%29+-+3c
(1) 39+=+6%2A16+%2B+12+-+3c
(1) 39+=+96+%2B+12+-+3c
(1) 3c+=+96+%2B+12+-+39
(1) 3c+=+108+-+39
(1) 3c+=+69
(1) c+=+23
and
(3) f+-+s+=+c
(3) 39+-+16+=+23
OK


logarithm/186597: Hi guys, im stumped with this one:
2ln2 - ln(x-1) = ln(2x)
solve for 'x'.
cheers =)
1 solutions

Answer 139860 by josmiceli(9698) About Me  on 2009-03-13 20:10:52 (Show Source):
You can put this solution on YOUR website!
In general:
log%28a%29+-+log%28b%29+=+log%28a%2Fb%29
and
a%2Alog%28b%29+=+log%28a%5Eb%29
2ln%282%29+-+ln%28x-1%29+=+ln%282x%29
ln%282%5E2%29+-+ln%28x-1%29+=+ln%282x%29
ln%284%2F%28x-1%29%29+=+ln%282x%29
4%2F%28x-1%29+=+2x
4+=+2x%2A%28x-1%29
4+=+2x%5E2+-+2x
2x%5E2+-+2x+-+4+=+0
x%5E2+-+x+-+2+=+0
%28x+-+2%29%28x+%2B+1%29+=+0
x+=+2
x+=+-1
check:
2ln%282%29+-+ln%28x-1%29+=+ln%282x%29
2ln%282%29+-+ln%282-1%29+=+ln%282%2A2%29
ln%284%29+-+ln%281%29+=+ln%284%29
ln%284%29+-+0+=+ln%284%29
OK
2ln%282%29+-+ln%28x-1%29+=+ln%282x%29
2ln%282%29+-+ln%28-1-1%29+=+ln%282%2A%28-1%29%29
The negative root doesn't work since
raising e to a power can't
result in a negative


Length-and-distance/186465: Two perpendicular lines intersect at point (9,2). If the x-intercept of one line is double the x-intercept of the other, find the possible sum(s) of these x- intercepts.
1 solutions

Answer 139827 by josmiceli(9698) About Me  on 2009-03-13 15:25:01 (Show Source):
You can put this solution on YOUR website!
One line would be
y+=+mx+%2B+b%5B1%5D
The other line would be
y+=+-%281%2Fm%29x+%2B+b%5B2%5D
b%5B1%5D and b%5B2%5D are the y-intercepts
------------------------
Let the x-intercepts be x%5B1%5D and x%5B2%5D
y+=+0 at the x-intercepts, so
0+=+m%2Ax%5B1%5D+%2B+b%5B1%5D
x%5B1%5D+=+-%28b%5B1%5D%2Fm%29
and
0+=+-%281%2Fm%29%2Ax%5B2%5D+%2B+b%5B2%5D
x%5B2%5D+=+m%2Ab%5B2%5D
x%5B1%5D+%2B+x%5B2%5D+=+m%2Ab%5B2%5D+-+b%5B1%5D%2Fm
and
y+=+mx+%2B+b%5B1%5D
2+=+9m+%2B+b%5B1%5D
b%5B1%5D+=+2+-+9m
and
2+=+-%281%2Fm%29%2A9+%2B+b%5B2%5D
b%5B2%5D+=+2+%2B+9%2Fm
Substituting:
x%5B1%5D+%2B+x%5B2%5D+=+m%2A%282+%2B+9%2Fm%29+-+%282+-+9m%29%2Fm
x%5B1%5D+%2B+x%5B2%5D+=+2m+%2B+9+-+2%2Fm+%2B+9
x%5B1%5D+%2B+x%5B2%5D+=+2%28m+-+1%2Fm%29+%2B+18 this is the answer
Suppose the slopes of the lines are
m+=+-3
-%281%2Fm%29+=+1%2F3
and the solution is (9,2)
the equations are:
y+=+-3x+%2B+b%5B1%5D
2+=+-3%2A9+%2B+b%5B1%5D
b%5B1%5D+=+2+%2B+27
b%5B1%5D+=+29
y+=+-3x+%2B+29 1st equation
and
y+=+%281%2F3%29%2Ax+%2B+b%5B2%5D
2+=+%281%2F3%29%2A9+%2B+b%5B2%5D
b%5B2%5D+=+2+-+3
b%5B2%5D+=+-1
y+=+%281%2F3%29%2Ax+-+1 2nd equation
Setting y+=+0 in both will find the x-intercepts
y+=+-3x+%2B+29
0+=+-3%2Ax%5B1%5D+%2B+29
x%5B1%5D+=+29%2F3
and
0+=+%281%2F3%29%2Ax%5B2%5D+-+1
x%5B2%5D+=+3
and
x%5B1%5D+%2B+x%5B2%5D+=+2%28m+-+1%2Fm%29+%2B+18
29%2F3+%2B+3+=+2%28-3+-+1%2F%28-3%29%29+%2B+18
29%2F3+%2B+9%2F3+=+2%28-3+%2B+1%2F3%29+%2B+18
29%2F3+%2B+9%2F3+=+-6+%2B+2%2F3+%2B+18
Multiply both sides by 3
29+%2B+9+=+-18+%2B+2+%2B+54
38+=+-16+%2B+54
38+=+38
OK






Exponential-and-logarithmic-functions/186562: This question is from textbook
The problem directions state: Solve the equation. Check for extraneous solutions.
49.) 2ln(-x)+7= 14
I understand you remove 7 from both sides, but I am wondering how I change this particular problem into exponential form and what is the set-up for exponential form! Thanks!
1 solutions

Answer 139818 by josmiceli(9698) About Me  on 2009-03-13 12:05:56 (Show Source):
You can put this solution on YOUR website!
2%2Aln%28-x%29+%2B+7+=+14
Subtract 7 from both sides
2%2Aln%28-x%29+=+7
ln%28-x%29+=+7%2F2
-x+=+e%5E%287%2F2%29
First of all, any number raised to any power cannot
be negative, so x+%3C+0
By my calculator,
x+=+-33.115


Length-and-distance/186467: A straight line is drawn through the point (3,4). the line cuts the axes at the points A and B such that the area of the triangle OAB is 24. Find the x-intercepts of all such lines
1 solutions

Answer 139784 by josmiceli(9698) About Me  on 2009-03-13 04:51:04 (Show Source):
You can put this solution on YOUR website!
Call the x-intercept x%5Bi%5D
Call the y-intercept y%5Bi%5D
Call the slope m
%281%2F2%29%2Ax%5Bi%5Dy%5Bi%5D+=+24
x%5Bi%5Dy%5Bi%5D+=+48
y%5Bi%5D+=+48%2Fx%5Bi%5D
and
m+=+-%28y%5Bi%5D%2Fx%5Bi%5D%29
m+=+-+%2848%2F%28x%5Bi%5D%29%5E2%29
The general equation is
y+=+mx+%2B+b and goes through (3,4)
and b is the y-intercept
4+=+m%2A3+%2B+b
4+=+3m+%2B+y%5Bi%5D
4+=+-3%2A%2848%2F%28x%5Bi%5D%29%5E2%29+%2B+y%5Bi%5D
4+=+-3%2A%2848%2F%28x%5Bi%5D%29%5E2%29+%2B+48%2Fx%5Bi%5D
4%2A%28x%5Bi%5D%29%5E2+=+-144+%2B+48x%5Bi%5D
4%2A%28x%5Bi%5D%29%5E2+-+48x%5Bi%5D+%2B+144+=+0
%28x%5Bi%5D%29%5E2+-+12x%5Bi%5D+%2B+36+=+0
%28x%5Bi%5D+-+6%29%5E2+=+0
x%5Bi%5D+=+6
The x-intercept is 6 answer
and
y%5Bi%5D+=+48%2Fx%5Bi%5D
y%5Bi%5D+=+48%2F6
y%5Bi%5D+=+8
check:
%281%2F2%29%2Ax%5Bi%5Dy%5Bi%5D+=+24
%281%2F2%29%2A6%2A8+=+24
24+=+24
m+=+-%28y%5Bi%5D%2Fx%5Bi%5D%29
m+=+-%288%2F6%29
m+=+-%284%2F3%29
The general equation is:
y+=+-%284%2F3%29%2Ax+%2B+8
does it go through (3,4)?
4+=+-%284%2F3%29%2A3+%2B+8
4+=+-4+%2B+8
4+=+4
OK



Quadratic_Equations/186482: What is the answer to f(x) = -3x2
1 solutions

Answer 139783 by josmiceli(9698) About Me  on 2009-03-13 04:09:26 (Show Source):
You can put this solution on YOUR website!
What is the question?


Equations/186495: Hello.
I'm needing some help with checking what I did wrong on this problem:
Perform the indicated operation and simplify
(s+t)(s^2-st+t^2)
thanks!
1 solutions

Answer 139779 by josmiceli(9698) About Me  on 2009-03-13 00:47:56 (Show Source):


Quadratic_Equations/186469: A fraternity charters a bus for a ski trip at a cost of $360. When 6 more students join the trip, each person's cost decreases by $2. How many students were in the original group of ravelers?
1 solutions

Answer 139741 by josmiceli(9698) About Me  on 2009-03-12 17:44:45 (Show Source):
You can put this solution on YOUR website!
Let n = number of student in original group
Let c = the original cost per person
given:
(1) n%2Ac+=+360
(2) %28n+%2B+6%29%28c+-+2%29+=+360
(2) n%2Ac+%2B+6c+-+2n++-+12+=+360
Substitute (1) in (2)
(2) 360+%2B+6c+-+2n+-+12+=+360
(2) 6c+=+2n+%2B+12
(2) c+=+n%2F3+%2B+2
Substitute this in (1)
(1) n%2A%28n%2F3+%2B+2%29+=+360
(1) n%5E2%2F3+%2B+2n+-+360+=+0
(1) n%5E2+%2B+6n+-+1080+=+0
Use quadratic formula
n+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
a+=+1
b+=+6
c+=+-1080
n+=+%28-6+%2B-+sqrt%28+6%5E2-4%2A1%2A%28-1080%29+%29%29%2F%282%2A1%29+
n+=+%28-6+%2B-+sqrt%28+36+%2B+4320+%29%29%2F2+
n+=+%28-6+%2B-+sqrt%28+4356+%29%29%2F2+
n+=+%28-6+%2B-+66%29%2F2
n+=+60%2F2
n+=+30
There were 30 students in the original group
check:
(1) n%2Ac+=+360
(1) 30%2Ac+=+360
(1) c+=+12
and
(2) %28n+%2B+6%29%28c+-+2%29+=+360
(2) %2830+%2B+6%29%2812+-+2%29+=+360
(2) 36%2A10+=+360
(2) 360+=+360
OK


Exponents/186458: Could someone help me with this problem:
(2/3)^-2(4/5)^-1
I am suppose to write it in simplest form without negative exponents.
I am usually good in algebra but since I got a new math teacher I feel I dont grasp anything anymore :(
1 solutions

Answer 139740 by josmiceli(9698) About Me  on 2009-03-12 17:23:52 (Show Source):
You can put this solution on YOUR website!
%282%2F3%29%5E-2%2A%284%2F5%29%5E-1
If you don't get negative exponents, just think of them
like this:
10^4 = 10000
10^3 = 1000
10^2 = 100
10^1 = 10
10^0 = 1
10^-1 = .1
10^-2 = .01
10^-3 = .001
10^-4 = .0001
In general, x%5E%28-a%29+=+1%2F%28x%5Ea%29
%282%2F3%29%5E-2%2A%284%2F5%29%5E-1
%281%2F%282%2F3%29%5E2%29%2A%281%2F%284%2F5%29%5E1%29
%281%2F%284%2F9%29%29%2A%281%2F%284%2F5%29%29
Now you just invert each fraction
%289%2F4%29%2A%285%2F4%29
45%2F16 answer


Systems-of-equations/186409: y=3x and x + y=2

answer: 1/2, 3/2
wanted to know how my book got these fractions as answer need full break down
1 solutions

Answer 139711 by josmiceli(9698) About Me  on 2009-03-12 11:28:03 (Show Source):
You can put this solution on YOUR website!
(1) y+=+3x and
(2) x+%2B+y+=+2
There are 2 equations and 2 unknowns. Whenever the
number of unknowns matches the number of equations,
then a solution is possible.
First, subtract y from both sides of (1)
(1) y+=+3x
(1) 0+=+3x+-+y
Now simply add (1) and (2)
(1) 3x+-+y+=+0
(2) x+%2B+y+=+2
(3) 4x+=+2
(3) x+=+1%2F2
To find y, substitute x+=+1%2F2 in (1)
(1) y+=+3x
(1) y+=+3%2A%281%2F2%29
(1) y+=+3%2F2
The solution is x+=+1%2F2 and y+=+3%2F2


Travel_Word_Problems/186407: From a point on a straight road, john and fred ride bicycles in opposite directions. john rides 5 miles per hour and fred rides 14 miles per hour. in how many hours will they be 57 miles apart?
1 solutions

Answer 139709 by josmiceli(9698) About Me  on 2009-03-12 11:18:21 (Show Source):
You can put this solution on YOUR website!
They are driving away from eachother
at a combined speed of 5+%2B+14+=+19 mi/hr
d+=+r%2At
57+=+19%2At
t+=+3
They will be 57 mi from eachother in 3 hrs


Linear-systems/186418: An Airplane flew for 4 hours against headwind of 40 km/h. On the
return flight the same wind was now a tail wind, and the flight took 3
hours. Find the speed of the airplane in still air
1 solutions

Answer 139708 by josmiceli(9698) About Me  on 2009-03-12 11:12:19 (Show Source):
You can put this solution on YOUR website!
Let p = speed of plane in still air
Let d = distance travelled one way
given:
d+=+%28p+-+40%29%2A4 (against wind)
d+=+%28p+%2B+40%29%2A3 (with wind)
Since both are equal to d, set them
equal to eachother
%28p+-+40%29%2A4+=+%28p+%2B+40%29%2A3
4p+-+160+=+3p+%2B+120
p+=+280
The speed of plane in still air is 280 mi/hr
check:
d+=+%28p+-+40%29%2A4
d+=+%28p+%2B+40%29%2A3
-------------------
d+=+%28280+-+40%29%2A4
d+=+240%2A4
d+=+960
d+=+%28p+%2B+40%29%2A3
d+=+%28280+%2B+40%29%2A3
d+=+320%2A3
d+=+960
OK


Mixture_Word_Problems/186415: a merchant has coffee worth $20 a pound that she wishes to mix with 80 pounds of coffee worth $90 a pound to get a mixture that can be sold for $60 a pound. how many pounds of the $20 coffee should be used?
1 solutions

Answer 139706 by josmiceli(9698) About Me  on 2009-03-12 11:01:40 (Show Source):
You can put this solution on YOUR website!
Let a= pounds of $20 coffee used
given:
20a= cost in dollars of $20 coffee used
80%2A90+=+7200 = cost in dollars of $90 coffee used
a+%2B+80 = pounds of coffee in final mixture
60%2A%28a+%2B+80%29 = cost in dollars of final mixture
-------------------
20a+%2B+7200+=+60%2A%28a+%2B+80%29
20a+%2B+7200+=+60a+%2B+4800
40a+=+2400
a+=+60
60 pounds of $20 coffee must be used
check:
20a+%2B+7200+=+60%2A%28a+%2B+80%29
20%2A60+%2B+7200+=+60%2A%2860+%2B+80%29
1200+%2B+7200+=+60%2A140
8400+=+8400
OK


Evaluation_Word_Problems/186343: Please help me quickly, I am trying to help my daughter with her homework.
Problem:
At a concert, main floor seats sell for $25.00 and Upper Level seats sell for $12.00. There were 50,000 people in attendance and the concert total ticket sales is $1,112,000. How many main floor seats and upper level seats were sold?
1 solutions

Answer 139675 by josmiceli(9698) About Me  on 2009-03-11 23:02:20 (Show Source):
You can put this solution on YOUR website!
Let m = number of main floor tickets sold
Let u = number of upper level tickets sold
given:
(1) m+%2B+u+=+50000
(2) 25m+%2B+12u+=+1112000
There are 2 equations and 2 unknowns. When the
number of equations matches the number of unknowns,
it is solvable.
Multiply both sides of (1) by 12
and subtract from (2)
(2) 25m+%2B+12u+=+1112000
(1) -12m+-+12u+=+-600000
(3) 13m+=+512000
(3) m+=+39385 (rounded off)
and
(1) m+%2B+u+=+50000
(1) 39385+%2B+u+=+50000
(1) u+=+10615 (rounded off)
39,385 mainfloor seats were sold and 10615 upper level
seats were sold
check answer:
(2) 25m+%2B+12u+=+1112000
(2) 25%2A39385+%2B+12%2A10615+=+1112000
(2) 984625+%2B+127380+=+1112000
(2) 1112005+=+1112000 (close enough)
and
(1) m+%2B+u+=+50000
(1) 39385+%2B+10615+=+50000
(1) 50000+=+50000
OK


Polynomials-and-rational-expressions/186269: i just need help in trying to solve this division of polynomials:
(24x2-19x+6)/(8x-1)
1 solutions

Answer 139629 by josmiceli(9698) About Me  on 2009-03-11 18:31:08 (Show Source):
You can put this solution on YOUR website!
The 1st partial answer is
3x
3x%2A%288x+-+1%29+=+24x%5E2+-3x
Subtract 24x%5E2+-+3x from 24x%5E2+-+19x+%2B+6
getting -16x+%2B+6
The 2nd partial answer is
-2
-2%2A%288x+-+1%29+=+-16x+%2B+2
Subtract -16x+%2B+2 from -16x+%2B+6
getting 4
The answer is 3x+-+2+%2B+4%2F%288x+-+1%29 (4 is the remainder)
If you multiply 3x+-+2+%2B+4%2F%288x+-+1%29 by 8x+-+1,
you get 24x%5E2+-+19x+%2B+6


Equations/186255: This question is from textbook Beginning Algebra
Could you please help me solve this problem?

Find three consecutive integers whose sum is -114.
1 solutions

Answer 139618 by josmiceli(9698) About Me  on 2009-03-11 17:55:51 (Show Source):
You can put this solution on YOUR website!
Let n be the smallest integer
Then n+%2B+1 is the next larger
And n+%2B+2 is the next larger
given:
n+%2B+n+%2B+1+%2B+n+%2B+2+=+-114
3n+=+-117
n+=+-39
n+%2B+1+=+-38
n+%2B+2+=+-37
The consecutive integers are -37, -38, and -39
check:
n+%2B+n+%2B+1+%2B+n+%2B+2+=+-114
-39+-+39+%2B+1+-+39+%2B+2+=+-114
-117+%2B+3+=+-114
-117+=+-117
OK


Mixture_Word_Problems/186265: a tea shop sells grea tea for $4.00 a pound and a white tea for $2.75 per pound. the manager decides to combine the two types of teas to make a mix that sells for $3.50 per pound. the mis should not cause any change in revenue. how much of each tea should combine to make a 10 pound mixture
1 solutions

Answer 139616 by josmiceli(9698) About Me  on 2009-03-11 17:45:53 (Show Source):
You can put this solution on YOUR website!
Let g= pounds of green tea needed
Let w= pounds of white tea needed
given:
(1) g+%2B+w+=+10 lb
4g+%2B+2.75w+=+3.5%2A10 dollars
(2) 4g+%2B+2.75w+=+35
Multiply both sides of (1) by 4 and
subtract (2) from (1)
(1) 4g+%2B+4w+=+40
(2) -4g+-+2.75w+=+-35
(3) 1.25w+=+5
(3) w+=+4
and
(1) g+%2B+w+=+10
(1) g+%2B+4+=+10
(1) g+=+6
4 pounds of white tea and 6 pounds of green tea are needed


Linear-systems/186085: This question is from textbook Algebra 1
How do you solve this linear system with substitution?
8x+3y=0
-x-9y=92
All I have got to is...
x=-9y-92
3y(-9y-92)=0
-6y-92=0
-6y=92
I dont think I did it right??
1 solutions

Answer 139526 by josmiceli(9698) About Me  on 2009-03-10 19:46:08 (Show Source):
You can put this solution on YOUR website!
(1) 8x+%2B+3y+=+0
(2) -x+-+9y+=+92
Subtract 3y from both sides of (1)
(1) 8x+=+-3y
Divide both sides by -3
(1) y+=+-%288%2F3%29%2Ax
Multiply the right side by 3%2F3
(1) y+=+-%2824%2F9%29%2Ax
Substitute this in (2)
(2) -x+-+9y+=+92
(2) -x+-+9%2A%28-%2824%2F9%29%29%2Ax+=+92
(2) -x+%2B+24x+=+92
(2) 23x+=+92
(2) x+=+4
And, from
(1) 8x+%2B+3y+=+0
(1) 8%2A4+%2B+3y+=+0
(1) 3y+=+-32
(1) y+=+-%2832%2F3%29
check answers:
(1) 8%2A4+%2B+3%2A%28-%2832%2F3%29%29+=+0
(1) 32+-+32+=+0
OK
(2) -4+-+9%2A%28-%2832%2F3%29%29+=+92
(2) -4+%2B+96+=+92
(2) 92+=+92
OK


Age_Word_Problems/186089: There are four children in a family. There were all born two years apart. The sum of their ages is 84. How old are the children?
1 solutions

Answer 139525 by josmiceli(9698) About Me  on 2009-03-10 19:30:40 (Show Source):
You can put this solution on YOUR website!
Let the youngest child's age be a
Their ages are then:
a, a+%2B+2, a+%2B+4,and a+%2B+6
a+%2B+a+%2B+2+%2B+a+%2B+4+%2B+a+%2B+6+=+84
4a+%2B+12+=+84
4a+=+72
a+=+18
a+%2B+2+=+20
a+%2B+4+=+22
a+%2B+6+=+24
Their ages are 18,20,22,and 24


Numbers_Word_Problems/186080: This question is from textbook Holt Algebra 1
The sum of Anji's age and Carol's age is 66. Carol's age is 2 more than 3 times Anji's age. How old are Carol and Anji?
1 solutions

Answer 139524 by josmiceli(9698) About Me  on 2009-03-10 18:49:14 (Show Source):
You can put this solution on YOUR website!
Let a= Anji's age
Let c= Carol's age
given:
(1) a+%2B+c+=+66
(2) c+=+3a+%2B+2
Subtract 3a from both sides of (2)
(2) -3a+%2B+c+=+2
Subtract (2) from (1)
(1) a+%2B+c+=+66
(2) -%28-3a%29+-+c+=+-2
(3) 4a+=+64
(3) a+=+16
and, since
(1) a+%2B+c+=+66
(1) 16+%2B+c+=+66
(1) c+=+50
Anji's age is 16, and Carol's age is 50
check:
(2) c+=+3a+%2B+2
(2) 50+=+3%2A16+%2B+2
(2) 50+=+48+%2B+2
(2) 50+=+50
OK


Miscellaneous_Word_Problems/186070: Pietro's Pizza and Sandwiches delivered lots of sandwiches one rainy Saturday. They took orders for 30 sandwiches with cheese, 25 with tomatoes, and 18 with pepperoni. there were 18 with cheese and tomato, 14 with tomato and pepperoni, and 10 with all three toppings. there were 8 with only cheese. how many sandwiches did they deliver?
i have worked with the numbers and the pizzas don't add up. i don't know if it is extra info.
1 solutions

Answer 139523 by josmiceli(9698) About Me  on 2009-03-10 18:32:23 (Show Source):
You can put this solution on YOUR website!
I come up with 37 sandwiches
I drew 3 interlocking circles with
an area in the middle common to
all three
Here's the breakdowns:
c only ---t only ---p only --- c&t --- t&p --- c&p
-----------------------------------------------------
----8--------3-------0--------18--------14------14
I add up:
8 c only
8 c&t only
3 t only
4 t&p only
0 p only
4 p&c only
10 All 3 toppings
-----
37


Polynomials-and-rational-expressions/186066: please help me with this polynomial.

z^2+9z+20

thank you and please show work so i know how to complete it on my own.
1 solutions

Answer 139522 by josmiceli(9698) About Me  on 2009-03-10 17:56:38 (Show Source):
You can put this solution on YOUR website!
This can be done by the method
known as
-completing the square-
Take 1%2F2 of the coefficient of
the z term, square it, then
add the results to both sides
-------------------------------
z%5E2+%2B+9z+%2B+20+=+0
But first, I have to get the constant
term on the other side. Subtract 20
from both sides
z%5E2+%2B+9z+=+-20
Now complete the square
z%5E2+%2B+9z+%2B+%289%2F2%29%5E2+=+-20+%2B+%289%2F2%29%5E2
z%5E2+%2B+9z+%2B+81%2F4+=+-20+%2B+81%2F4
With this method, the left side always ends up
being a perfect square. In this problem, both
sides are a perfect square
%28z+%2B+%289%2F2%29%29%5E2+=+-%2880%2F4%29+%2B+81%2F4
%28z+%2B+%289%2F2%29%29%5E2+=+1%2F4
Now take the square root of both sides,
both the (+) and (-) square root
z+%2B+9%2F2+=+1%2F2
z+=+-%289%2F2%29+%2B+1%2F2
z+=+-4
and
z+%2B+9%2F2+=+-%281%2F2%29
z+=+-%289%2F2%29+-%281%2F2%29
z+=+-5
-4 and -5 are the roots of the polynomial
To factor z%5E2+%2B+9z+%2B+20,
z+=+-4
z+-%28-4%29+=+0
z+%2B+4+=+0
and
z+-%28-5%29+=+0
z+%2B+5+=+0
The factoring is:
%28z+%2B+4%29%28z+%2B+5%29+=+z%5E2+%2B+9z+%2B+20


Length-and-distance/186064: This question is from textbook Pre-Algebra
brandon hikes 7 miles south and 4 west. How far is he from the starting point of his hike?
1 solutions

Answer 139521 by josmiceli(9698) About Me  on 2009-03-10 17:35:09 (Show Source):
You can put this solution on YOUR website!
Call the distance from his starting point d
By the pythagorean theorem for a right triangle:
d%5E2+=+7%5E2+%2B+4%5E2
d%5E2+=+49+%2B+16
d%5E2+=+65
d+=+sqrt%2865%29
d+=+8.062 mi


Graphs/185934: Soybean meal in 16% protein; cornmeal is 8% protein. How many pounds of each should be mixed together in order to get 320-lb mixture that is 10% protein?
1 solutions

Answer 139446 by josmiceli(9698) About Me  on 2009-03-10 00:02:58 (Show Source):
You can put this solution on YOUR website!
Let s= pounds of soybean meal needed
Let c= pounds of cornmeal needed
given:
.16s= pounds of protein in soybean meal needed
.08c= pounds of protein in cornmeal needed
320= pounds of final mixture
--------------
(1) %28.16s+%2B+.08c%29%2F320+=+.1
(2) s+%2B+c+=+320
Multiply both sides of (1) by 320
(1) .16s+%2B+.08c+=+.1%2A320
(1) .16s+%2B+.08c+=+32
Multiply both sides of (2) by .08
(2) .08s+%2B+.08c+=+25.6
Subtract (2) from (1)
(1) .16s+%2B+.08c+=+32
(2) -.08s+-+.08c+=+-25.6
(3) .08s+=+6.4
(3) s+=+80
and
(2) s+%2B+c+=+320
(2) 80+%2B+c+=+320
(2) c+=+240
80 pounds of soybean meal and 240 pounds of cornmeal
are needed
check:
(1) %28.16%2A80+%2B+.08%2A240%29%2F320+=+.1
(1) %2812.8+%2B+19.2%29%2F320+=+.1
(1) 32%2F320+=+.1
(1) .1+=+.1
OK