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Recent problems solved by 'Earlsdon'

Earlsdon answered: 6281 problems
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Sequences-and-series/497220: the formalua you use to find the sum of 1-1000 1+2=3+3=6+4=10+5=15 ..... Thank you! 1 solutions Answer 336703 by Earlsdon(6287)   on 2011-09-13 21:43:05 (Show Source): You can put this solution on YOUR website! Here's the formula: Where: is the first number (That's number 1), is the nth number (that's 1000), and is the number of numbers (that's 1000). So... =500,500

Angles/497233: Find the measure of an angle such that the difference between its supplement and 3 times its complement is 34 degrees. I ended up trying to solve it and came up with -28, but that doesn't sound right. Can someone explain and help me solve this equation? 1 solutions Answer 336693 by Earlsdon(6287)   on 2011-09-13 21:00:46 (Show Source): You can put this solution on YOUR website! Let the angle you're looking be A, then: (180-A)-3(90-A) = 34 Simplify and solve for A. 180-A-270+3A = 34 2A-90 = 34 2A = 124 A = 62 degrees.

Equations/496609: Have no idea how to do it? 1 solutions Answer 336504 by Earlsdon(6287)   on 2011-09-12 23:16:58 (Show Source): You can put this solution on YOUR website! Do what????

Square-cubic-other-roots/496592: Can you please help me with this problem: 1 solutions Answer 336503 by Earlsdon(6287)   on 2011-09-12 23:16:09 (Show Source): You can put this solution on YOUR website! Solve for x: Square both sides. Rewrite this as: Solve by factoring: or so... or

Radicals/496600: How could I solve this radical equation? 4sqrt ( x-3)= 0 Thank you!! 1 solutions Answer 336502 by Earlsdon(6287)   on 2011-09-12 23:09:24 (Show Source): You can put this solution on YOUR website! Solve for x: Square both sides.

Rectangles/496596: the area of a rectangle is 144 square meters. the length of the rectangle is three times it's width. find the length and width of the rectangle. 1 solutions Answer 336501 by Earlsdon(6287)   on 2011-09-12 23:06:06 (Show Source): You can put this solution on YOUR website! The area of a rectangle is given by: Substitute Divide by 3. Take the square root of both sides. meters. meters.

Geometry_Word_Problems/495505: When the lengths of all four sides of a square are multipled the result is 1296. What is the preimeter of the square? 1 solutions Answer 336112 by Earlsdon(6287)   on 2011-09-11 17:21:06 (Show Source): You can put this solution on YOUR website! Let s = the length of one side of the square. Take the fourth root of both sides. The perimeter (P) of the square is:

Numbers_Word_Problems/495527: twenty-one less than the product of seven and the difference of a number and one is three times the number. what is the number? 1 solutions Answer 336105 by Earlsdon(6287)   on 2011-09-11 17:06:10 (Show Source): You can put this solution on YOUR website! If n is the required number, the problem can be expressed as: Simplify and solve for n. Add 28 to both sides. Subtract 3n from both sides. Divide both sides by 4. The number is 7.

Mixture_Word_Problems/495507: Solution A is 50% alcohol. Solution B is 20% alcohol. We want to create a 20 liter mixture of the two solutions that will be 32% alcohol. How many liters of each solution should be used? 1 solutions Answer 336102 by Earlsdon(6287)   on 2011-09-11 16:59:58 (Show Source): You can put this solution on YOUR website! Let x = the required number of liters of solution A (50% alcohol solution), then (20-x) will be the number of liters of solution B (20% alcohol solution). The sum of these is to be 20 liters of 32% alcohol solution. This situation can be expressed (after changing the percentages to their decimal equivalents) in the following equation: Simplify and solve for x. Combine the x-terms. Subtract 4 from both sides. Finally, divide both sides by 0.3 liters and... liters. You will need to mix 8 liters of solution A (the 50% alcohol solution) with 12 liters of solution B (the 20% alcohol solution) to obtain 20 liters of 32% alcohol solution.

Geometry_Word_Problems/495496: you have 480 feet of fencing to enclosea rectangular garden you want the length of the gardrn to be 30 ft greater than the width find the length and width of the garden if you use all the fencing 1 solutions Answer 336099 by Earlsdon(6287)   on 2011-09-11 16:42:46 (Show Source): You can put this solution on YOUR website! When the fence is finished, its perimeter (P) will be 480 feet. The formula for the perimeter of a rectangle is: The length and W is the width, so... Simplify and solve for W. Divide both sides by 2. Subtract 30 from both sides. Divide by 2. feet, and... feet. Check: OK!

Numeric_Fractions/495481: Can you please help me with this question? This question is for h.w that's due tomorrow and I really need help. Please do not just answer the question but show how you got to the answer and all the work involved in it. Thanks so much! Problem: Suppose you own a card shop. You buy one line of cards at a rate of 4 cards for $5. You plan to sell the cards at a rate of 3 cards for $5. How many cards must you sell in order to make a profit of $100? Please solve with all the work as soon as possible! Thanks so much! :) 1 solutions Answer 336093 by Earlsdon(6287)   on 2011-09-11 16:32:12 (Show Source): You can put this solution on YOUR website! Let the number of cards you need to sell be x. Recall that Profit (P) = Selling price (S) - Cost (C). P = S-C The profit is to be P = $100.00 The selling price That is x times $5.00 per 3 cards. The cost That is x times $5.00 per 4 cards. So the equation would be: Solve for x. Multiply both sides by 12. Divide by 5. You would have to sell 240 cards to make a profit of $100.00 Check: Selling price of 240 cards at 3 cards for $5.00 is: = and... The cost of 240 cards at $5.00 for 4 cards is =

expressions/495330: Trying to factor -18a^2 + 17a + 15. All I can get at this point is multiplying -18 with 15 equals -270. 1 solutions Answer 336053 by Earlsdon(6287)   on 2011-09-11 12:22:18 (Show Source): You can put this solution on YOUR website! Try this: FIrst factor a -1. What are the factors of 18? 1*18 = 18 2*9 = 18 3*6 = 18 And what are the factors of 15? 1*15 = 15 3*5 = 15 I would start with 2*9 and 3*15 but you can start with any pairs from both groups and check your solutions..

test/495332: How do you define a variable? For example: Define a variable and write an algebraic expression for this phrase: the difference of 8 and a number. 1 solutions Answer 336052 by Earlsdon(6287)   on 2011-09-11 12:12:23 (Show Source): You can put this solution on YOUR website! Just let n = the number you're looking for, that's the variable and you've just defined it. Now you can write the expression asked for: "The difference of eight and a number (n)."

Equations/494279: How do I get x by itself in 2x+6xy+5bx=5 ? 1 solutions Answer 335591 by Earlsdon(6287)   on 2011-09-08 22:21:30 (Show Source): You can put this solution on YOUR website! Since each term on the left has a factor of x, you can factor this x out to get: Now divide both sides by ():

Finance/494261: The area of a rectangular field is 9000 square meters. If the ratio of the width to the length is 5 is to 8, what is the length of the rectangular field in meters? 1 solutions Answer 335589 by Earlsdon(6287)   on 2011-09-08 22:17:40 (Show Source): You can put this solution on YOUR website! Since you have the ratio of the width to the length, this is 5 t0 8, then you know that the width is some multiple of 5 and the length is the same multiple of 8. We'll let this multiple be x, so you have and , and the area is expressed as: Simplify and solve for x: Divide both sides by 40. Take the square root of both sides. This is the multiple, so... = This is the width, W. = This is the length, L.

Equations/493008: How do you rewrite this equation for y: y-2xy= 15 1 solutions Answer 335257 by Earlsdon(6287)   on 2011-09-07 16:24:20 (Show Source): You can put this solution on YOUR website! Factor out the y. Divide both sides by ().

Equations/493029: please help me solve this word problem one fifth of the orange crop at Pulp Farms was destroyed by frost. One half of the remaindr was sent in a shipment of 1600 crates to be processed into orange juice. How many crates of oranges were destroyed? 1 solutions Answer 335254 by Earlsdon(6287)   on 2011-09-07 16:20:57 (Show Source): You can put this solution on YOUR website! Let x = the total number of crates of the entire orange crop. The number of crates of oranges destoyed by frost = thus leaving a remainder of crates to be processed into orange juice. But one half of this remainder was sent to be processed into orange juice and this amounted to 1600 crates. Setting up the equation in terms of x, we get: Multiply both sides by the multiplicative inverse of which is we get: crates in the total orange crop. One fifth of this total was destroyed by frost, so... crates. 800 crates of oranges were destroyed by frost.

Linear-equations/493005: I need to create and solve an equation, but I don't know how. The problem is: A moving company weighs 20 boxes you have packed that contain either books or clothes and says that the total weight is 404 pounds. You know that a box of books weighs 40 pounds and a box of clothes weighs 7 pounds. How many boxes of books and how many of clothes did you pack? 1 solutions Answer 335245 by Earlsdon(6287)   on 2011-09-07 16:05:14 (Show Source): You can put this solution on YOUR website! Let B = the number of boxes of books and their total weight will then be B*(40lbs). The number of boxes of clothes will be (20-B) and their total weight will be (20-B)*(7lbs). The sum of the weights of all of these boxes will be 404lbs. Let's write the equation that models this situation: B*(40)+(20-B)*(7) = 404 Simplify this and solve for B. 40B+140-7B = 404 Subtract 140 from both sides. 40B-7B = 264 33B = 264 Divide both sides by 33. B = 8 and 20-B = 12. There were 8 boxes of books and 12 boxes of clothes.

real-numbers/492245: Hi I have a word problem and I don't quite understand it. Could you please help figure out how to slove it? Here is the question/problem: A dolphin starts at the surface of the water. It dives down at the rate of 3 feet per second. If the water level is zero, what real number descrides the dolphin's location after 3 1/2seconds? Thank-you 1 solutions Answer 334999 by Earlsdon(6287)   on 2011-09-06 17:36:42 (Show Source): You can put this solution on YOUR website! First. since the dolphin is diving (that's below sea-level) the number of feet here will be a negative number. Let's see how far below sea-level the dolphin will have travelled below the surface in 3.5 seconds at the rate of 3 feet per second. (3 ft./sec)(3.5 secs) = 10.5 feet. But of course, this is a negative number so the answer would be: -10.5

Geometry_Word_Problems/492273: My rectangular soccer field site has a length equal to twice its width. Find its area in terms of its length x 1 solutions Answer 334989 by Earlsdon(6287)   on 2011-09-06 17:14:35 (Show Source): You can put this solution on YOUR website! Start with the formula for the area of a rectangle: Let L(length) = x and W(Width) = 2x.

Square-cubic-other-roots/491388: Can you explain why x=plus/minus (2/3)^3/2 simplifies to: x=(2 square root of 6)/(9)? 1 solutions Answer 334630 by Earlsdon(6287)   on 2011-09-05 11:52:39 (Show Source): You can put this solution on YOUR website! ====

Points-lines-and-rays/491185: E is the midpoint of segment DF, DE= 2x + 4, and EF= 3x - 1. Find DE, EF and DF. 1 solutions Answer 334520 by Earlsdon(6287)   on 2011-09-04 21:08:26 (Show Source): You can put this solution on YOUR website! Since E is the midpoint of DF, then DE = EF, so... 2x+4 = 3x-1 Subtract 2x from both sides. 4 = x-1 Add 1 to both sides. x = 5 DE = 2x+4 Substitute x = 5. DE = 2(5)+4 DE = 14 EF = 3x-1 Substitute x = 5. EF = 3(5)-1 EF = 14 DF = 14+14 DF = 28.

test/490947: The price in dollars of a gallon of gasoline at the end of each month is recorded for one year. The results are: 1.19 1.28 1.55 1.76 1.85 1.85 1.83 1.76 1.66 1.52 1.48 1.47 Find the mode of these prices. Please help me!!Thanks so much 1 solutions Answer 334372 by Earlsdon(6287)   on 2011-09-04 11:15:45 (Show Source): You can put this solution on YOUR website! Recall that the mode of a set of numbers is the most frequently-occuring number in the set. A set may have no mode, one mode, or more than one mode. It helps to put the numbers in order (ascending or descending). 1.19, 1.28, 1.47, 1.48, 1.52, 1.55, 1.66, 1.76, 1.76, 1.83, 1.85, 1.85 As you can see, the numbers 1.76 and 1.85 appear two times each so these are the modes.

Numbers_Word_Problems/490950: Here is my word problem that I do now know how to solve: If a number is increased by 14 and the result is multiplied by 2/3 the answer is 60. Find the orginal number. Thank you! 1 solutions Answer 334371 by Earlsdon(6287)   on 2011-09-04 11:05:26 (Show Source): You can put this solution on YOUR website! Let n = the missing number, then... "If a number (n) is increased by 14 and the result is multiplied by , the answer is 60." Multiply both sides by Simplify. Subtract 14 from both sides.

Miscellaneous_Word_Problems/490937: If Mary can paint a house in 4 hours and it takes John 6 hours to paint the same house, how long would it take them if they worked together? The answer is 2 hours and 44 minutes. I just cannot get there...HELP!! 1 solutions Answer 334368 by Earlsdon(6287)   on 2011-09-04 10:56:41 (Show Source): You can put this solution on YOUR website! Find the hourly rate of each painter. If Mary can paint the house in 4 hours, then she can paint of the house in 1 hour. If John can paint the house in 6 hours, then he can paint of the house in 1 hour. So working together, they can paint of the house in 1 hour, which means that they can paint the entire house in hours. hours. or hours and minutes.

Polynomials-and-rational-expressions/490548: help solve the following: factor completely -6x^6-30x^5+84x^4 1 solutions Answer 334173 by Earlsdon(6287)   on 2011-09-03 10:44:56 (Show Source): You can put this solution on YOUR website! Factor completely: Rewrite this as: Now factor the common factor of and you'll get: Notice the sign changes inside the parentheses. Now factor the quadratic expression in the parentheses.

test/490572: The weight in pounds of ten randomly-selected football players are: 245, 304, 310, 251, 195 185, 230, 264, 315, 196 Find the median of these weights. Please help me!!Thanks a lot 1 solutions Answer 334168 by Earlsdon(6287)   on 2011-09-03 10:23:44 (Show Source): You can put this solution on YOUR website! The "median" of a set of numbers is the middle number, so put your ten numbers in numerical order, from smallest to largest, then find the middle number. 185, 195, 196, 230, 245, 251, 264, 304, 310, 315. Notice that you have an even number of numbers so there is no single middle number. In this case, you select the two middle numbers, add them and divide by two. The two middle numbers are: 245 and 251. Add 'em up to get 496. Now divide by 2 to get 248. The median is 248.

Age_Word_Problems/490361: At a family reunion 3 cousins were comparing there ages. Jennifer is 17 years younger than Rene and Rene is 10 years older then Melissa. Their ages total 60 years. How old is Rene? 1 solutions Answer 334043 by Earlsdon(6287)   on 2011-09-02 18:38:24 (Show Source): You can put this solution on YOUR website! Let J = Jennifer's age, R = Rene's age, and M = Melissa's age. J = R-17 "Jennifer is 17 years younger than Rene." R = M+10 "Rene is 10 years older than Melissa." J+R+M = 60 "Their ages total 60 years." Find Rene's age. Start with: J+R+M = 60 Now substitute J = R-17 from the first equation. (R-17)+R+M = 60 Now substitute M = R-10 from the second equation. R-17+R+R-10 = 60 Combine like-terms. 3R-27 = 60 Add 27 to both sides. 3R = 87 Divide both sides by 3. R = 29 Rene is 29 years old.

Radicals/490260: I'm trying to understand how to simplify this fraction with radicals square root of 540 ------------------- 3 square root of 5 I know the answer is 2 square root of 3 I have tried multiplying it by the denominator 1 solutions Answer 333959 by Earlsdon(6287)   on 2011-09-02 11:42:33 (Show Source): You can put this solution on YOUR website! Simplify: Write 540 as 15*36 Now take the square root of 36 (that's 6) and move it outside of the radical. Cancel 3's and rewrite the square roots as: Now cancel the 5's to get:

Polynomials-and-rational-expressions/490153: how do you factor a problem like v to the 4th power minus 1296 1 solutions Answer 333893 by Earlsdon(6287)   on 2011-09-02 01:22:31 (Show Source): You can put this solution on YOUR website! How about: Now factor the difference of two squares: Now factor the difference of squares again: Now put it all together to get: or

Linear_Algebra/490180: My daughter is frustrated in Algebra II (well all math in general that is). She was given homework in which I cannot assist her with; It's been about 25-years for me. I was good at it, but need a refresher in order to assist her. Here is a simple graphing problem: y = x - 2 y = -2x + 7 Her book seems to miss some of the steps and I don't remember what to do. According to the answers at the back of the book her graph was in error on one of the positive lines (on the x axis she began at -7). What is the correct way to solve this simple problem? 1 solutions Answer 333891 by Earlsdon(6287)   on 2011-09-02 01:10:56 (Show Source): You can put this solution on YOUR website! This is a "system of equations" or "simultaneous equations (at least, where I went to school)" y = x-2 and y = -2x+7 Now since y = y, you can just set the two equations equal to each other thus: x-2 = -2x+7 and solve for x. Add 2x to both sides. 3x-2 = 7 Now add 2 to both sides. 3x = 9 Finally, divide both sides by 3. x = 3 Now you must replace the x in either of the two given equations and solve for y. y = -2x+7 Substitute x = 3. y = -2(3)+7 Evaluate. y = -6+7 y = 1 The solution is (3, 1) Another way is to graph the two given equations and find the point of intersection (if any) of the two lines. The lines intersect at (3, 1)