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

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

Question 74952: on farm there are 77 animals, all horses and hens. the 77 animals have a total of 262 legs. how many horses and hens are there? justify your answer.
Click here to see answer by bucky(2189)

Question 74951: on a farm there are 65 animals, all cows and ducks. The 65 animals have a total of 224 legs. How many cows and ducks are there? Justify your answer.
Click here to see answer by ptaylor(2048)

Question 74954: Jamal has a collection of bugs. all of them are either ladybugs or spiders. he has a total of 27 bugs. altogether they have 194 legs. how many ladybugs and spiders does he have? justify you answer.
Click here to see answer by ptaylor(2048)

Question 75149: Eric is preparing to run in the Bay Marathon. One day, he ran and walked a total of 16 miles. If he ran one mile more than twice as far as he walked, how many miles did he run? Thank you for helping
Click here to see answer by checkley75(3666)

Question 75152: I don't really understand this.. well i kind of do but i kind of don't:
3x+2y=12
2x+5y=8
I don't know how to do it because there is no "y=" or "x=" and it get confused on these. would you take (3x+2y=12) and multiply that by negative 2... and then take (2x+5y=8) and multiply that by positive 3?.... i don't know.. but if thats correct, I don't know what to do next.
Click here to see answer by Earlsdon(6287)

Question 75209: Perform Indicated Operation
(5x^2-7x+2)-(3x^2-4x-7)
Click here to see answer by alan(1)

Question 75209: Perform Indicated Operation
(5x^2-7x+2)-(3x^2-4x-7)
Click here to see answer by jim_thompson5910(28593)

Question 75214: Can someone explain the basic principles for the substituion method? I would like to know what can make it easier to understand if at all possible. Thanks!

Click here to see answer by jim_thompson5910(28593)

Question 75401: A bicyclist rode into the country for 5 hours. In returning, her speed was 5 mi/hour faster and the trip took 4 hours. What was her speed each way?
r*t=d

Click here to see answer by rmromero(383)

Question 75506: Social science. If there are 6 x 10(9th power) people on the Earth and there is enough freshwater
to provide each person with 8.79 x 10(5th power) L, how much freshwater is on the
Earth?
thanks
Click here to see answer by checkley75(3666)

Question 75519: how do you find the correlation coefficient
Click here to see answer by chitra(359)

Question 75771: Evaluate the expression.
12 – (3 + 1) + 3/4

Click here to see answer by stanbon(57323)

Question 75763: Write the following phrase using symbols. Use the variable p to represent the number in each case.
2 more than 6 times a number divided 3

Click here to see answer by bucky(2189)

Question 75756: Evaluate the expression: 48 divided by(8-4) - 2
Click here to see answer by checkley75(3666)

Question 75815: How many ounces of pure gold must be added to five ounces of something that is 1 percent gold in order that the mixture is 6 percent gold?
Click here to see answer by josmiceli(9671)

Question 75813: solve for x by completing the square: x^2+6x=2
Click here to see answer by bucky(2189)

Question 75814: solve x^2-7x-3=0 for x.
Click here to see answer by checkley75(3666)

Question 75894: I have variables on both sides: 7p-12 = 3p
Click here to see answer by checkley75(3666)

Question 75919: Please help me factor. thanks
1000x^3+1
Click here to see answer by Earlsdon(6287)

Question 75916: How do you solve . Using substitution. Our teacher has given us this practice with no review from her. I don't know where to start using substitution.
Click here to see answer by ankor@dixie-net.com(15649)

Question 75918: I need help with factoring. I can't seem to get it, especially when there is an X first. Please help me. thanks
X^3-125
Click here to see answer by Earlsdon(6287)

Question 75905: j^2-9jk-10k^2
Click here to see answer by checkley75(3666)

Question 76123: Solve each of the following systems by substitution
8x - 4y =16
y = 2x - 4

Click here to see answer by Earlsdon(6287)

Question 76125: Solve each of the following systems by substitution
4x - 12y = 5
-x + 3y = -1

Click here to see answer by checkley75(3666)

Question 76266: Rewrite the equation y = 5x – 5 as a function of x.
Click here to see answer by aaaaaaaa(138)

Question 76258: Rewrite the equation 4x – 10y = 11 as a function of x.
Click here to see answer by tutorcecilia(2152)

Question 76265: Given f(x) = –4x – 4, find f(2).
Click here to see answer by tutorcecilia(2152)

Question 76263: Solve the system by substitution.
x + y = 12
y = 2x

Click here to see answer by tutorcecilia(2152)

Question 76479: Solve the system by addition or substitution.
10x-5y=17
y=2x-3
Click here to see answer by chitra(359)

Question 76480: Solve the system by graphing.
x+y=3
x+y=-1
Click here to see answer by chitra(359)

Question 76478: Solve the system by substitution.
3x-y=-7
x+y=-9
Click here to see answer by chitra(359)

Question 76477: Solve the system by graphing.
x-2y=8
x+y=-1
Click here to see answer by Edwin McCravy(8908)

Question 76476: Given f(x)=-4x-4, find f(2).
Click here to see answer by checkley75(3666)

Question 76551: I think I'm using the correct area. I need to simplify the following expression. Any help would be great. Thank you so much!
2x^2-18y^2/3y-x
Click here to see answer by rmromero(383)

Question 76690: Given f(x) = 2x + 5, find f(a – 1).
These are my choices
2a + 3
2a + 4
a + 6
a + 3

Click here to see answer by stargrl12566(16)

Question 76702: Please help me solve for x, y, and z.
x/2 + y/5 + z/3= 17
x/5 + y/2 + z/5= 32
x + y/3 + z/2= 30
Click here to see answer by Edwin McCravy(8908)

Question 77068: Solve the system by substitution.
x + 3y = –8
5x + 2y = 12

Click here to see answer by tutorcecilia(2152)

Question 77145: Hello out there,I don't know if I'm in the wrong area or not but I need some help with some variation problems,the first one is,Assume that y varies inversely as x,and y=18 when x=3.Find the constant of variation.The next one is,Assume that y varies inversely as x.If y=8 when x=2.5,find x when y=2.The next one is,Is it true that 1-y=2x is a direct variation,or is it false.And the last one is,well this one is really confusing,it's something about domain problems,A teacher wises to schedule a quiz or exam during part of a two-hour class.The equation L+E=120 can be used to find the available lecture time "L" given that "E" minutes are planned for the quiz or exam.Determine the ordered pairs that satisfy the equation if the domain is {20,30,45,60}.Thank you for whoever can assit me.
Click here to see answer by stanbon(57323)

Question 77317: A=P+Prt, for r A=$880, P=800, t=2years
Click here to see answer by jim_thompson5910(28593)

Question 77336: 2-(x-1/4)=x+2/3
Click here to see answer by ptaylor(2048)

Question 77335: 2-(x-1/4)=x+2/3
Click here to see answer by jim_thompson5910(28593)

Question 77424: 6X TP THE POWER OF 2 Y TO THE POWER OF 3 + 9X TO THE POWER OF 2 Y TO THE POWER OF 3 OVER 3X TO THE POWER OF 2 Y TO THE POWER OF 2 =
Click here to see answer by Edwin McCravy(8908)

Question 77443: a triangle has sides 3x+7, 4x-9, and 5x+6 whats the expression that represents its perimeter
Click here to see answer by vikved(3)

Question 77442: 4b+5d-c/a=
Click here to see answer by stanbon(57323)

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