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

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

Question 66167: -z=7=-3
Click here to see answer by checkley71(8403)

Question 66199: -13 is the difference of a number multiplied by 5 and 8
Click here to see answer by checkley71(8403)

Question 66339: Please help with this problem solving by substitution:
3x + 4y = 8
4.5x + 6y = 12
This is what I got:
3x + 4y = 8
4y = 8 - 3x
y = 2 - .75x
Then:
3x + 4(2-.75x) = 8
3x + 8 - 3x = 8
3x - 3x = 8 - 8
0 = 0
I don't understand what I'm doing wrong. Please help!
Thank you, Alison.
Click here to see answer by stanbon(57422)

Question 66355: Words To Expressions :
Directions: Change It Into An expression
Easy Example: five minus three: 5-3=(dont solve)
The product of three and two minus eight:
Click here to see answer by checkley71(8403)

Question 66519: 1x+1=2x-1
Click here to see answer by checkley71(8403)

Question 66551: solve for x:
3x - 2y = 6

option of solutions that i need to pick from are:
A) 2y + 6 divided by 3
B)3x - 6 divided by 2
C) 2 + 2y
D) 2/3y + 6

how do you even solve this problem.
Click here to see answer by Gen(11)

Question 66596: Celsius temperature readings can be converted to
Fahrenheit readings using the formula F = 9/5 C + 32

What is the Fahrenheit temperature that corresponds to each of the following Celsius temperatures -10, 0, 15, 100?

Click here to see answer by funmath(2925)

Question 66631: x/6 +3 = 9
Click here to see answer by stanbon(57422)

Question 66611: Compare equations with one variable to equations with two variables.
How are they alike? How are they different?What if an equation had three variables?
Click here to see answer by Poohbear272(22)

Question 66632: what if an equation had three variables what is the difference and similarieties between those equations that have one and/or two variable?
Click here to see answer by Poohbear272(22)

Question 66625: what is the difference and similarities
if solving an equation with varibles in the equation if it had 1 or 2 or even 3 variables?
Click here to see answer by Poohbear272(22)

Question 66616: Subtract and write in simplest form:
12 10
---- - ----
z z
I believe the answer is:
2
---
z^2
Is this correct? Thank you
Click here to see answer by funmath(2925)

Question 66685: y varies directly with n; m = 144 when n = 8.
Click here to see answer by Nate(3500)

Question 66731: y=-2x-1
y=3x-16
-2x-1=3x-16
-1=5x-16
15=5x
3=x
y=-2(3)-1
y=-6-5
y=-11

Click here to see answer by stanbon(57422)

Question 66729: What would the answer be for 12+2(k+3)=3k-6?
Could you please show the work so i can understand it.
Click here to see answer by stanbon(57422)

Question 66729: What would the answer be for 12+2(k+3)=3k-6?
Could you please show the work so i can understand it.
Click here to see answer by Edwin McCravy(8921)

Question 66748: You decide to market your own custom computer system. You must invest $5874 in computer hardware and spend $4.85 to buy and package each disk. If each program sells for $13.75, how many copies must you sell to break even?

Here are the multiple choice answers:
A. 660 copies
B. 316 copies
C. 315 copies
D. 659 copies
Click here to see answer by rapaljer(4667)

Question 66730: Suppose you try to solve systems of linear equations using substitution and get x=8.How many solutions does each system have?
Click here to see answer by rapaljer(4667)

Question 66448: if 5^21*4^11=2*10^n what is value of n
Click here to see answer by rapaljer(4667)

Question 66794: Am having troubles figuring out the 2 expressions to use in solving this problem: The sum of 2 number is 311. One quarter of the larger is four more than the smaller number. What are the two numbers.
I know the first expression is x + y = 311
I can't figure out how to make the second expression to solve for both.(does that make sense?)
Thank you for whatever help you can give. I'm most frustrated with this at the moment and I'm sure it's something simple I'm missing.
Click here to see answer by ptaylor(2048)

Question 66805: BOOKS A LIBRARY HAS 14,588 BOOKS WHICH FILL ITS 313 EQUAL-SIZE SHELVES. NEW SHELVES OF WHAT IS THE AVERAGE NUMBER OF BOOKS PER SHELF? THE LIBRARY PLANS TO INSTALL 50 NEW SHELVES OF THIS SIZE. WRITE AND SOLVE AN EQUATION TO ESTIMATE HOW MANY MORE BOOKS THE LIBRARY WILL BE ABLE TO HOLD.
Click here to see answer by stanbon(57422)

Question 66809: Would you please help me solve this question?:
The constant slope of a snowpark for boarders can be modeled by the line passing through the point A(1,5) and Point B(7,1). What is the equation of the line that models the terrain of the snowpark? Express your answer in the form:
y = mx + b where m and b are common fractions..

Click here to see answer by ankor@dixie-net.com(15667)

Question 66830: Find three consecutive even numbers so that when I double the largest and then add the smallest, I get 116. Write an equation and solve.
Trial and Error:
36,38,40
40+40=80 Largest Doubled
80+36=116 Largest Doubled + Smallest

Click here to see answer by checkley71(8403)

Question 66950: I have a question regarding the correct setup of this sentence.
"The larger of 2 numbers is 8 more than 4 times the smaller. If the larger is increased by 4 times the smaller, the result is 40. Find the numbers!"
Any help would be great!!! This question is not out of the textbook, it is from a hand out from the teacher.
Click here to see answer by ptaylor(2048)

Question 66973: how would i simpligy this expression sqrt 16a^4x^2
Click here to see answer by stanbon(57422)

Question 66932: please help me solve this: i am not sure what to do.
(1/3)-(2/x-2)+(1/x+1)
Thank you Chelsie
Click here to see answer by stanbon(57422)

Question 67006: 0.25x+0.05y=2.75
Click here to see answer by stanbon(57422)

Question 67062: Al, Betty, and Claire, slipt $1000 among them to be invested in different ways. Each begins with a different amount. At the end of one year they have a total of $1500. Betty and Claire have both doubled their money, whereas Al had managed to lose $100. What was Al's original portion?
Click here to see answer by ankor@dixie-net.com(15667)

Question 67168: Mr.James wanted to plant a garden that would be in the shape of a rectangle . He was given 80ft. of fencing to enclose his garden. He wants the length to be 10ft. more than twice the width. What are the dimensions, in feet, for a rectangular garden that will use exactly 80ft. of fencing?
Click here to see answer by Zoop(21)

Question 67342: Hi, I need help with the following: Thanks in advance!

1. Jeff makes 5 dollars per hour plus $7.50 as a one time start fee. Write an expression for how much Jeff made after x hours.

2. A scuba diving hotel offers divers two plans. Plan A gives 3 nights' lodging and 4 dives. Plan B gives 5 nights' lodging and 8 dives. Let x be the number of dollars they charge per night and y be the number of dollars per dive. Write two expressions, one for the amount you would pay for Plan A and the other for Plan B.

3. The waitress at a restaurant makes $32 per day and the cook makes $50 per day. In addition they divide the tips received in such a way that the waitress gets 70% and the cook gets 30%. Let x be the number of dollars in tips in a day. Write an expression for the total amount of money (wages and tips) the waitress and cook make a day (one equation per person).

Click here to see answer by ptaylor(2048)

Question 67406:
Click here to see answer by lovelyn_316(1)

Question 67581: Could you please help me with this problem. When a) x = 2, b) x = -3
5x + 2
---------------
2x^2 + 11x + 12

This is what I tried..
5(2)+ 2
__________ = 12 12 12
2(3)^2 + 11(-3) + 12 _________________ = _______________ = _____ = 4
18 - 33 + 12 -15 + 12 -3
Click here to see answer by funmath(2925)

Question 67606: how do u solve 4x+7(2x-1)=12
Click here to see answer by checkley71(8403)

Question 67805: How can you simplify x to the "a" minus x to the "b"?
Click here to see answer by adamchapman(301)

Question 68103: The Quotient of 3b and 4.5
Click here to see answer by Edwin McCravy(8921)

Question 68200: Is 4 a solution to the equation x + 7 = 11?
Click here to see answer by funmath(2925)

Question 68201: Which expression describes the sequence below, when 'n' is the position in the sequence?
3, 8, 13, 18, ....
a) 5n + 3
b) 5n - 2
c) 2n + 1
d) n + 2
Click here to see answer by checkley71(8403)

Question 67653: x+5y=28
-x-2y=-13
Click here to see answer by rmromero(383)

Question 68399: 4x+12 < -2x-6
I've tried solving this problem, but when I check it, I am supposed to replace the variable with the answer I got and the answer is supposed to be equal.
I checked it, but I keep getting 16=4.
Click here to see answer by stanbon(57422)

Question 68454: how do isolve the formula to the giving value C = K - 273 for K?
Click here to see answer by tutorcecilia(2152)

Question 68436: F1 + c1Q = f2 + c2Q
Solve for Q
I keep getting either 2Q or a Q-Q ... can you help

Click here to see answer by ankor@dixie-net.com(15667)

Question 68543: what does it mean when there is a line over a variable?
Click here to see answer by funmath(2925)

Question 68673: Evaluate the expression below for the given values.

A). -4d+3 if d=-1 B). k-m if k=4 and m=-10
Click here to see answer by rmromero(383)

Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485, 1486..1530, 1531..1575, 1576..1620, 1621..1665, 1666..1710, 1711..1755, 1756..1800, 1801..1845, 1846..1890, 1891..1935, 1936..1980, 1981..2025, 2026..2070, 2071..2115, 2116..2160, 2161..2205, 2206..2250, 2251..2295, 2296..2340, 2341..2385, 2386..2430, 2431..2475, 2476..2520, 2521..2565, 2566..2610, 2611..2655, 2656..2700, 2701..2745, 2746..2790, 2791..2835, 2836..2880, 2881..2925, 2926..2970, 2971..3015, 3016..3060, 3061..3105, 3106..3150, 3151..3195, 3196..3240, 3241..3285, 3286..3330, 3331..3375, 3376..3420, 3421..3465, 3466..3510, 3511..3555, 3556..3600, 3601..3645, 3646..3690, 3691..3735, 3736..3780, 3781..3825, 3826..3870, 3871..3915, 3916..3960, 3961..4005, 4006..4050, 4051..4095, 4096..4140, 4141..4185, 4186..4230, 4231..4275, 4276..4320, 4321..4365, 4366..4410, 4411..4455, 4456..4500, 4501..4545, 4546..4590, 4591..4635, 4636..4680, 4681..4725, 4726..4770, 4771..4815, 4816..4860, 4861..4905, 4906..4950, 4951..4995, 4996..5040, 5041..5085, 5086..5130, 5131..5175, 5176..5220, 5221..5265, 5266..5310, 5311..5355, 5356..5400, 5401..5445, 5446..5490, 5491..5535, 5536..5580, 5581..5625, 5626..5670, 5671..5715, 5716..5760, 5761..5805, 5806..5850, 5851..5895, 5896..5940, 5941..5985, 5986..6030, 6031..6075, 6076..6120, 6121..6165, 6166..6210, 6211..6255, 6256..6300, 6301..6345, 6346..6390, 6391..6435, 6436..6480, 6481..6525, 6526..6570, 6571..6615, 6616..6660, 6661..6705, 6706..6750, 6751..6795, 6796..6840, 6841..6885, 6886..6930, 6931..6975, 6976..7020, 7021..7065, 7066..7110, 7111..7155, 7156..7200, 7201..7245, 7246..7290, 7291..7335, 7336..7380, 7381..7425, 7426..7470, 7471..7515, 7516..7560, 7561..7605, 7606..7650, 7651..7695, 7696..7740, 7741..7785, 7786..7830, 7831..7875, 7876..7920, 7921..7965, 7966..8010, 8011..8055, 8056..8100, 8101..8145, 8146..8190, 8191..8235, 8236..8280, 8281..8325, 8326..8370, 8371..8415, 8416..8460, 8461..8505, 8506..8550, 8551..8595, 8596..8640, 8641..8685, 8686..8730, 8731..8775, 8776..8820, 8821..8865, 8866..8910, 8911..8955, 8956..9000, 9001..9045, 9046..9090, 9091..9135, 9136..9180, 9181..9225, 9226..9270, 9271..9315, 9316..9360, 9361..9405, 9406..9450, 9451..9495, 9496..9540, 9541..9585, 9586..9630, 9631..9675, 9676..9720, 9721..9765, 9766..9810, 9811..9855, 9856..9900, 9901..9945, 9946..9990, 9991..10035, 10036..10080, 10081..10125, 10126..10170, 10171..10215, 10216..10260, 10261..10305, 10306..10350, 10351..10395, 10396..10440, 10441..10485, 10486..10530, 10531..10575, 10576..10620, 10621..10665, 10666..10710, 10711..10755, 10756..10800