Questions on Algebra: Expressions involving variables, substitution answered by real tutors!

Tutors Answer Your Questions about Expressions-with-variables (FREE)

Question 90614: A manufacturer has determined that the revenue received from selling x items of a product is given by R(x) = -0.3x2 + 200x and the cost to produce x items of the product is given by C(x) = 80x + 9400. Assuming that all of the products produced can be sold, how many should be produced to maximize the profit? (Hint: profit = revenue - cost)
I have such a hard time with word problems. I reall appreciate the help
Click here to see answer by scott8148(6628)

Question 90857: The cost C in dollars to remove p% of the pollution in a small pond near a factory is given by C(p) = 5000p/100-p, 0<-p<100 , Find the cost of removing 75% of the pollution.
Click here to see answer by stanbon(57412)

Question 91114: A car radiator has a capacity of 16 quarts and is filled with a 25% Anti-freeze solution. How much must be drained off and replaced with pure Anti-freeze to obtain a 40% Anti-freeze solution?
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Question 91317: quotients of expression involving exponents
vu^6/v^3u^4
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Question 91348: (t+2)/t + 3/(t+1) =?
I cannot remember what to do for the first step please help.
Click here to see answer by tutor_paul(490)

Question 91698: write the expression for each quantity
1. the value in cents of 5 quarters
2. the value in cents of q quarters
3.the number of months in 7 years
4. the number of monthes in y years
5. the number of gallons in 21 quarts
6.the number of gallons in q quarts ?
i dont get it ? plz help
Click here to see answer by scott8148(6628)

Question 91750: 3w-13=1/4(52-12w)
3w-13=13-3w

First, i know i have to distribute 1/4 to 52 and -12w.
Then, i'm stuck, i know that the answer is 4 1/3 but i don't know how to get that answer. PLEASE HELPP!

Click here to see answer by stanbon(57412)

Question 91867: I have this assignment and my calcualtor doesn't evaluate logarithisms and exponents. And I can't find the formula to write the expression In x = 4 in exponential notation.

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Question 91990: 7(4w-3)-25w
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Question 91999: add rational expressions with common denominator
3y-3x/5y - 4y+8x/5y
Thank you so very much for the help
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Question 92000: add rational expression with common denomiation
-8z-2u/-7z - 9z-9u/7z
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Question 92004: Add and write your answer to lowest terms
-9w-6x/7w + 7w-2x/7w
Thak you for the help
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Question 91888: Our galaxy is estimated to be 5.6 x 10^19 mi across. How long (in hours) would it take a spaceship to cross the galaxy traveling at 37,500 mph.
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Question 92156: please help me with this problem Thank you in advance
x + Y=12
Y=2X
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Question 92155: Please help me solve this problem thank you in advance
sol:-since x=2/3 therefore substitute value of x in eq 1 e.g. 3(2/3)+6y=0then 2+6y=0 then 6y=-2 ory=-1/3
Click here to see answer by sanjay_jb007(1)

Question 92171: Translate and simplify: "quantity three less than twice the sum of a number and 5".
Click here to see answer by stanbon(57412)

Question 92213: A.) Linear Growth A town has a fixed increase in population growth number of population increase each year. population 1897. Find the growth rates for the following
I don't get this at all?
Year (t) Population (P)
t = 0 Po = 1897
(2010)
t = 1
(2011)
t = 2
(2012)
t = 3
(2013)
t = 6
(2016)
B.) Find a linear equation in the form P = mt + b (y = mx + b), which gives the population, P, t years from 2010.
Click here to see answer by bucky(2189)

Question 92114: 6q+9
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Question 92113: I'm suppose to make a table showing the value of each expression when the value of the variable is 1,2,3,4,and 5. I don't understand how I'm suppose to do that?
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Question 92269: The problem is 3x^2 - 10x = 8
I got x = 6 as shown below except when I plug it in it doesn't work.
3x^2/x = 10x+8/x
3x = 18
x = 6

Click here to see answer by checkley71(8403)

Question 92331: Please help me I am having some problems with this question this is from a worksheet.
solve the system by addititon or substitution
3x + 6y = 0
x=2/3
Click here to see answer by jim_thompson5910(28598)

Question 92333: solve the system by substitution
x + y = 12
-x + y = 2
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Question 92334: please help me this is from a worksheet thank you in advance.
solve the system by addition or substitution
3x - 4y=8
6x-2y =10
Click here to see answer by jim_thompson5910(28598)

Question 92393: a number to the second power is called squared and one to the third power is called cubed. what is it called to the 4th and 5th power?
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Question 92335: please help me I am having trouble with this problem thank you in advance
solve the system by addition and substitution
3x -4x = 8
6x - 2y = 10
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Question 92414: the product of x and 7
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Question 92413: the sum of b and 21

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Question 92537: 4x squared minus 1
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Question 92739: Are there any values of the variable a for which the expressions 2+a and 2a have the same value? Explain.
Click here to see answer by jim_thompson5910(28598)

Question 92748: This might be a stupid question but, it's bothering me so here it is: Evaluate the expression for the given value of x : x=-1
I'm not sure if I'm supposed to put the -1 in parentheses because if I do I get a different answer.
Look: or --1^2+-1-1=-1
Which is it?
Click here to see answer by bucky(2189)

Question 92749: the value in cents of 5 quarters
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Question 92820: If 2r = 5s and 5s = 6t, what does r equal in terms of t?
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Question 92918: Hey this is Debbie and I am having trouble understanding this.
For these linear functions complete the table of values by substitution.
b=a+3
a 0 1 2 3 4 5 10
b
I am having trouble working how to do substitution because I forgot how to do it.Must help appreciated.
Click here to see answer by scott8148(6628)

Question 92952: Solve for y. x + 3y = 12
Click here to see answer by jim_thompson5910(28598)

Question 93097: Simplify the expression. Assume that the vaiables in the denominator are non-zero.
(4/xy^2) -3
This is hard to type but it looked like a fraction in big parenthesis as 4 over xy to the -3 power. Thanks so much!!
Click here to see answer by tutorcecilia(2152)

Question 93240: The number of gallons in q quarts
Click here to see answer by Earlsdon(6287)

Question 93242: 1. The value in cents of 5 quarters
Click here to see answer by Nate(3500)

Question 93319: Can you help me with this problem? Solve for x. x+2y= -1
3x-4y= 27
I think I am supposed to solve for y in one problem, then substitute it in the next one... but I'm not sure. Thanks in advance!!!
Click here to see answer by stanbon(57412)

Question 93314: Can you please help me with this problem? Solve for x. x+2y= -1
3x-4y= 27
I think I am supposed to solve for the y variable in one problem, then plug it in for the next one. I'm not sure though. Thank you in advance!!!
Click here to see answer by checkley75(3666)

Question 93320: I NEED HELP ON THIS PROBLEM. I DON'T UNDERSTAND HOW TO FIGURE IT OUT. THANKS
Click here to see answer by ankor@dixie-net.com(15661)

Question 93353: -5(3x-4)-(6x-1)
Click here to see answer by HayleyAlyce(8)

Question 93353: -5(3x-4)-(6x-1)
Click here to see answer by praseenakos@yahoo.com(507)

Question 93357: if you have a question that says simply the expresion how do you do it?
simplify 3(5x-6)-(6x+1)
Click here to see answer by checkley75(3666)

Question 93351: I have a few more problems. Can you please show me how to solve these problems such as:
7(6-(-8)) = t/-4 +2,
4x+5 = 3x-3,
6y=5 = 4y-13,and
7p-8 = -4p+6.
Thank you.

Click here to see answer by praseenakos@yahoo.com(507)

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