Algebra ->  Tutoring on algebra.com -> See tutors' answers!      Log On

 Tutoring Home For Students Tools for Tutors Our Tutors Register Recently Solved
 By Tutor
| By Problem Number |

Tutor:

# Recent problems solved by 'richwmiller'

Jump to solutions: 0..29 , 30..59 , 60..89 , 90..119 , 120..149 , 150..179 , 180..209 , 210..239 , 240..269 , 270..299 , 300..329 , 330..359 , 360..389 , 390..419 , 420..449 , 450..479 , 480..509 , 510..539 , 540..569 , 570..599 , 600..629 , 630..659 , 660..689 , 690..719 , 720..749 , 750..779 , 780..809 , 810..839 , 840..869 , 870..899 , 900..929 , 930..959 , 960..989 , 990..1019 , 1020..1049 , 1050..1079 , 1080..1109 , 1110..1139 , 1140..1169 , 1170..1199 , 1200..1229 , 1230..1259 , 1260..1289 , 1290..1319 , 1320..1349 , 1350..1379 , 1380..1409 , 1410..1439 , 1440..1469 , 1470..1499 , 1500..1529 , 1530..1559 , 1560..1589 , 1590..1619 , 1620..1649 , 1650..1679 , 1680..1709 , 1710..1739 , 1740..1769 , 1770..1799 , 1800..1829 , 1830..1859 , 1860..1889 , 1890..1919 , 1920..1949 , 1950..1979 , 1980..2009 , 2010..2039 , 2040..2069 , 2070..2099 , 2100..2129 , 2130..2159 , 2160..2189 , 2190..2219 , 2220..2249 , 2250..2279 , 2280..2309 , 2310..2339 , 2340..2369 , 2370..2399 , 2400..2429 , 2430..2459 , 2460..2489 , 2490..2519 , 2520..2549 , 2550..2579 , 2580..2609 , 2610..2639 , 2640..2669 , 2670..2699 , 2700..2729 , 2730..2759 , 2760..2789 , 2790..2819 , 2820..2849 , 2850..2879 , 2880..2909 , 2910..2939 , 2940..2969 , 2970..2999 , 3000..3029 , 3030..3059 , 3060..3089 , 3090..3119 , 3120..3149 , 3150..3179 , 3180..3209 , 3210..3239 , 3240..3269 , 3270..3299 , 3300..3329 , 3330..3359 , 3360..3389 , 3390..3419 , 3420..3449 , 3450..3479 , 3480..3509 , 3510..3539 , 3540..3569 , 3570..3599 , 3600..3629 , 3630..3659 , 3660..3689 , 3690..3719 , 3720..3749 , 3750..3779 , 3780..3809 , 3810..3839 , 3840..3869 , 3870..3899 , 3900..3929 , 3930..3959 , 3960..3989 , 3990..4019 , 4020..4049 , 4050..4079 , 4080..4109 , 4110..4139 , 4140..4169 , 4170..4199 , 4200..4229 , 4230..4259 , 4260..4289 , 4290..4319 , 4320..4349 , 4350..4379 , 4380..4409 , 4410..4439 , 4440..4469 , 4470..4499 , 4500..4529 , 4530..4559 , 4560..4589 , 4590..4619 , 4620..4649 , 4650..4679 , 4680..4709 , 4710..4739 , 4740..4769 , 4770..4799 , 4800..4829 , 4830..4859 , 4860..4889 , 4890..4919 , 4920..4949 , 4950..4979 , 4980..5009 , 5010..5039 , 5040..5069 , 5070..5099 , 5100..5129 , 5130..5159 , 5160..5189 , 5190..5219 , 5220..5249 , 5250..5279 , 5280..5309 , 5310..5339 , 5340..5369 , 5370..5399 , 5400..5429 , 5430..5459 , 5460..5489 , 5490..5519 , 5520..5549 , 5550..5579 , 5580..5609 , 5610..5639 , 5640..5669 , 5670..5699 , 5700..5729 , 5730..5759 , 5760..5789 , 5790..5819 , 5820..5849 , 5850..5879 , 5880..5909 , 5910..5939 , 5940..5969 , 5970..5999 , 6000..6029 , 6030..6059 , 6060..6089 , 6090..6119 , 6120..6149 , 6150..6179 , 6180..6209 , 6210..6239 , 6240..6269 , 6270..6299 , 6300..6329 , 6330..6359 , 6360..6389 , 6390..6419 , 6420..6449 , 6450..6479 , 6480..6509 , 6510..6539 , 6540..6569 , 6570..6599 , 6600..6629 , 6630..6659 , 6660..6689 , 6690..6719 , 6720..6749 , 6750..6779 , 6780..6809 , 6810..6839 , 6840..6869 , 6870..6899 , 6900..6929 , 6930..6959 , 6960..6989 , 6990..7019 , 7020..7049 , 7050..7079 , 7080..7109 , 7110..7139 , 7140..7169 , 7170..7199 , 7200..7229 , 7230..7259 , 7260..7289 , 7290..7319 , 7320..7349 , 7350..7379 , 7380..7409 , 7410..7439 , 7440..7469 , 7470..7499 , 7500..7529 , 7530..7559 , 7560..7589 , 7590..7619 , 7620..7649 , 7650..7679 , 7680..7709 , 7710..7739 , 7740..7769 , 7770..7799 , 7800..7829 , 7830..7859 , 7860..7889 , 7890..7919 , 7920..7949 , 7950..7979 , 7980..8009 , 8010..8039 , 8040..8069 , 8070..8099 , 8100..8129 , 8130..8159 , 8160..8189 , 8190..8219 , 8220..8249 , 8250..8279 , 8280..8309 , 8310..8339 , 8340..8369 , 8370..8399 , 8400..8429 , 8430..8459 , 8460..8489 , 8490..8519 , 8520..8549 , 8550..8579 , 8580..8609 , 8610..8639 , 8640..8669 , 8670..8699 , 8700..8729 , 8730..8759 , 8760..8789 , 8790..8819 , 8820..8849 , 8850..8879 , 8880..8909 , 8910..8939 , 8940..8969 , 8970..8999 , 9000..9029 , 9030..9059 , 9060..9089 , 9090..9119 , 9120..9149, >>Next

 Age_Word_Problems/258779: Solve this problem by using a two order system. John is 5 years older than Mary. In 10 years, twice John's age decreased by Mary's age is 35, and John's age will be twice Mary's current age. Find their ages now. John is years old ?, and Mary is ? years old. 1 solutions Answer 190494 by richwmiller(9143)   on 2010-01-20 10:43:45 (Show Source): You can put this solution on YOUR website!Again no idea what you mean by "two order system" j=m+5 and 2(j+10)-(m+10)=35 and j+10=2m j=20 m=15 We can solve by just using the first and last equations. j=m+5 j+10=2m m+5+10=2m m+15=2m 15=m j=20 Just for fun lets check using the unused equation 2(j+10)-(m+10)=35 2(30)-25=35 60-25=35 35=35 ok
 Divisibility_and_Prime_Numbers/258679: 42is 21% of what number?1 solutions Answer 190491 by richwmiller(9143)   on 2010-01-20 10:31:16 (Show Source): You can put this solution on YOUR website!21%=.21 .21x=42 multiply by 100 21x=4200 x=4200/21=200
 Linear_Algebra/258778: 2x-4y=6 2x+y=1 my teacher said to solve this by using substitution but i keep getting the worng answer, help plz :)!1 solutions Answer 190489 by richwmiller(9143)   on 2010-01-20 10:23:35 (Show Source): You can put this solution on YOUR website!So what did you try? What did you get? 2x-4y=6 2x+y=1 Substitution might be the harder way to solve this Elimination would be Subtract the two and get -5y=5 y=-1 2x-1=1 2x=2 x=1 However we will do it by substitution. Solve the second for y y=1-2x Substitute 1-2x for y in the first 2x-4(1-2x)=6 2x-4+8x=6 10x =10 x=1 y=1-2(1) y=1-2 y=-1 Same answers
 Miscellaneous_Word_Problems/258760: The cost of a bus trip was \$180. he people who signed up for the trip agreed to split the cost equally. However, six people did not show up , so that those who did go each had to pay \$1.50 more. How many people actually went on the trip ? 1 solutions Answer 190487 by richwmiller(9143)   on 2010-01-20 10:17:05 (Show Source): You can put this solution on YOUR website!p*c=180 and (p-6)(c+1.5)=180 p=30 planned to go c=6 original cost per person p-6=24 went on trip c+1.50=7.50 cost per person on trip
 Linear-systems/258775: Solve this problem by using a two order system. One of two complementary angles is 8 degrees less than the other. The numbers are__?__degrees and __?__degrees . 1 solutions Answer 190485 by richwmiller(9143)   on 2010-01-20 10:11:56 (Show Source): You can put this solution on YOUR website!No idea what "two order system" means. a+b=90 a-b=8 2a=98 a=49 b=41
 Travel_Word_Problems/258761: jacqui commutes 30 miles to her job each day. She finds that if she drives 10 miles/hour faster, it takes her 6 minutes less to get to work .find her new speed1 solutions Answer 190482 by richwmiller(9143)   on 2010-01-20 10:06:58 (Show Source): You can put this solution on YOUR website!rt=30 t=30/r (r+10)(t-1/10)=30 (r+10)(30/r-1/10)=30 r=50 new speed 50+10=60 60(t-1/10)=30 t=3/5=36/60= 36 minutes t-1/10=new time 30 minutes
 Unit_Conversion_Word_Problems/258568: HELP! I'm an old dog learning new stuff. I'm having trouble getting this to click in my old brain. I'm supposed to figure this out by using dimensional analysis.... Thanks so very much for your help! If a block of ice measures 24 in. x 36 in. x 18 in. (a) What is the volume of this block in cubic meters? (b) What is the total surface area of the block in square centimeters? 1 solutions Answer 190386 by richwmiller(9143)   on 2010-01-19 19:46:01 (Show Source): You can put this solution on YOUR website!You need your conversion factor to convert from cubic inches to cubic meters and square inches to square centimeters 1 inches = 0.0254 meters http://vulcan.wr.usgs.gov/Miscellaneous/ConversionTables/conversion_table.html you can convert before multiplying or after
 Expressions-with-variables/258566: 1. Suppose you are at the gas station filling your tank with gas. The function C(g) represents the cost C of filling up the gas tank with g gallons. Given the equation: 1 solutions Answer 190381 by richwmiller(9143)   on 2010-01-19 19:35:08 (Show Source): You can put this solution on YOUR website!c(g)=g*p where p is the price per gallon
 Money_Word_Problems/258557: if someone has 360 dollars in his savings account in the bank he earns 3% interest each month how much interest would he earn in one month1 solutions Answer 190373 by richwmiller(9143)   on 2010-01-19 19:13:49 (Show Source): You can put this solution on YOUR website!It is hard to find 3% annual interest let alone 3% monthly!
 Linear-systems/258522: alright here goes lol. i tryed to solve it and came up with some strange answers. 1. 4x+2y+z=7 2x+2y-4z=-4 x+3y-2z=-8 My attempts: (sorry for the confusing factor x.x) (4x+2y+z=7)4 2x+2y-4z=28 _____________ 2x+2y=-4 16x+8y+28 ___________ 18x+10y=24 (4x+2y+z=7)2 x+3y-2z=-8 ____________ 8x+4x+2z=7 (9x+7y=-1)-2 18x+10y=24 ____________ -18x-14y=2 18x+10y=24 ___________ -4y = 26 ___ ___ -4 -4 y=-6.5 18x+10(-6.5)=24 18x-65=24 __________ 18x=89 x=4.94 4(4.94)+2(-6.5)+z=7 19.70-13+z=7 6.76+z=7 z=.24 thats it. im sorry its so confusing. im so very confused about this stuff so please help x.x1 solutions Answer 190336 by richwmiller(9143)   on 2010-01-19 18:18:55 (Show Source): You can put this solution on YOUR website!x = 3, y = -3, z = 1 Now for your attempt (4x+2y+z=7)4 2x+2y-4z=28 _____________ 2x+2y=-4 16x+8y+28 (4x+2y+z=7) *4 16x+8y+4z=28 What happened to the 4z and why only three terms? From here on it is trouble. Let's try again 4x+2y+z=7 (1) 2x+2y-4z=-4 (2) x+3y-2z=-8 (3)
 percentage/258451: estimate 8% of 621 solutions Answer 190314 by richwmiller(9143)   on 2010-01-19 17:42:24 (Show Source): You can put this solution on YOUR website!estimate 8 to be 10 estimate 62 to be 60 1/10 0f 60 is about 6
 Linear-equations/258517: I don't understand slopes and it seems difficult and i just don't understand it, please help!! Lynn1 solutions Answer 190307 by richwmiller(9143)   on 2010-01-19 17:33:46 (Show Source): You can put this solution on YOUR website!Most new things seem difficult. Give an example of the type of slope problem that stumps you. There are too many aspects of slope to go into them all without an example of your troubles.
 Sequences-and-series/258505: How do you get the sum 10 with the numbers; 2, 4, 9, and 3? 1 solutions Answer 190304 by richwmiller(9143)   on 2010-01-19 17:26:13 (Show Source): You can put this solution on YOUR website!9+3-2 9+4-3 (3*4)-2 Do I have to use all of them? That's harder. ((9*2)/3)+4 step one 2*9=18 step two 18/3=6 step three 6+4=10
 Triangles/258450: If a triangle has two short sides that are each three and four inches in length, how long is the longest side?1 solutions Answer 190295 by richwmiller(9143)   on 2010-01-19 17:02:30 (Show Source): You can put this solution on YOUR website!If we knew that the angle between the two short sides is a right angle then the third side would be 5. We do know that the third side must be less than 7.
Polynomials-and-rational-expressions/258463: factoring by using trial factors 6z^2-7z+3.
1 solutions

Answer 190292 by richwmiller(9143)   on 2010-01-19 16:55:39 (Show Source):
You can put this solution on YOUR website!
Solved by pluggable solver: Factoring using the AC method (Factor by Grouping)
In order to factor , first multiply the leading coefficient 6 and the last term 3 to get 18. Now we need to ask ourselves: What two numbers multiply to 18 and add to -7? Lets find out by listing all of the possible factors of 18

Factors:

1,2,3,6,9,18,

-1,-2,-3,-6,-9,-18, List the negative factors as well. This will allow us to find all possible combinations

These factors pair up to multiply to 18.

1*18=18

2*9=18

3*6=18

(-1)*(-18)=18

(-2)*(-9)=18

(-3)*(-6)=18

note: remember two negative numbers multiplied together make a positive number

Now which of these pairs add to -7? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to -7

||||||
 First Number | Second Number | Sum 1 | 18 | 1+18=19 2 | 9 | 2+9=11 3 | 6 | 3+6=9 -1 | -18 | -1+(-18)=-19 -2 | -9 | -2+(-9)=-11 -3 | -6 | -3+(-6)=-9

None of these factors add to -7. So the quadratic cannot be factored.

 Travel_Word_Problems/258487: In June 2007, Carl Edwards won the Michigan 400 with a time of 2:42:5 for the 400 mi race. At one point, Edwards was 80 mi closer to the finish than the start. How far had Edwards traveled at that point?1 solutions Answer 190289 by richwmiller(9143)   on 2010-01-19 16:48:13 (Show Source): You can put this solution on YOUR website!At 200 miles he was equal distance from the start and finish. At 220 he was 180 from the finish and 220 from the start- a difference of 40 At 240 he was 160 from the finish and 240 from the start a difference of 80 miles.
 Proportions/258481: how do u write 3 equivalent ratios for 2/91 solutions Answer 190286 by richwmiller(9143)   on 2010-01-19 16:43:34 (Show Source): You can put this solution on YOUR website!4/18 by multiplying by 2/2 6/27 by multiplying by 3/3 8/36 by multiplying by 4/4 10/45 by multiplying by 5/5 12/54 by multiplying by 6/6
 Numbers_Word_Problems/258382: Sales tax in California is 6%. Create an equation for the total price (cost plus tax) of a purchase in CA in terms of its cost. How much would a person pay for a car whos cost is \$32,000?1 solutions Answer 190259 by richwmiller(9143)   on 2010-01-19 14:23:45 (Show Source): You can put this solution on YOUR website!Sales tax in California has not been 6% for many many years.
 Linear_Equations_And_Systems_Word_Problems/258432: An airplane travels 900 miles from Houston to Miami in 6 hours against the wind. On its trip, with the wind, it takes only 5 hours. Find the rate of the airplane with no wind. Find the rate of the wind1 solutions Answer 190258 by richwmiller(9143)   on 2010-01-19 14:19:05 (Show Source): You can put this solution on YOUR website!rt=d r*6=900=3*300=3*2*150=150 s*5=900=6*150=6*30*5=180 180-150=30 30/2=15 mph wind airplane 165 mph with no wind.
 Square-cubic-other-roots/258436: How do I compute 5 2 - + - 6 91 solutions Answer 190256 by richwmiller(9143)   on 2010-01-19 14:13:15 (Show Source): You can put this solution on YOUR website!5/6+2/9=15/18+4/18=19/18=1 1/18
 Numbers_Word_Problems/258441: There are 220 barrels of cement in one shed and 510 barrels in another shed. How many barrels must be transferred from the second to the first shed so that the first shed will contain two-thirds as much as the second shed?1 solutions Answer 190255 by richwmiller(9143)   on 2010-01-19 14:10:15 (Show Source): You can put this solution on YOUR website!(220+x)=2/3*(510-x) x=72 to be moved 220+72=292 510-72=438 Note it does NOT say two thirds of the total barrels are in one place but the barrels in one place are two thirds of the barrels in the other
 Rectangles/258402: Children need to build a pen for their puppy using 24 square feet of fencing at .75 per foot. What is the dimensions and cost of the least expensive pen and the most expensive pen they can build?1 solutions Answer 190251 by richwmiller(9143)   on 2010-01-19 14:04:58 (Show Source): You can put this solution on YOUR website!If the children are going to build using 24 sqft there is no least nor most expensive. The quantity has been decided. Your price .75 ft doesn't make sense. The fencing is square feet.
 Miscellaneous_Word_Problems/258411: You have 1 gallon of solution that is 20% salt and 80% water. You need 8 gallons of solution that is 2% salt and 98% water. How much water do you add to obtain this?1 solutions Answer 190234 by richwmiller(9143)   on 2010-01-19 13:16:50 (Show Source): You can put this solution on YOUR website!.8*1+x=8*.98 7.04 gallons which works out in the equation but seems odd because 1 + 7.04 is more than 8 but if you add only 7 gallons it will tell that you are missing .04 gallons Maybe the salt is absorbed into the solution? .8*1+7=.98x x=7.95918
 Linear-equations/258418: A printer has two presses. One has a setup cost of \$210 and can print the pages of a certain book for \$5.69. The other press has a setup cost of \$350 and can print the pages of the same book for \$5.31. Find the break point. Could someone help me, please? Thank you.1 solutions Answer 190233 by richwmiller(9143)   on 2010-01-19 13:01:33 (Show Source): You can put this solution on YOUR website!210+5.69x=350+5.31x x=368.421 books is the break point where they cost the same and becomes cheaper to use the \$350 set up
 Square-cubic-other-roots/258419: evaluate the expression 25- ^3/41 solutions Answer 190232 by richwmiller(9143)   on 2010-01-19 12:49:01 (Show Source): You can put this solution on YOUR website!I assume you mean 25^(-3/4) which equals sqrt(5)/(25)
 Money_Word_Problems/258413: alicia murphy has a choice of two sizes of stain and varnish.the 237 milliliter can sells for 3.96 while the 946 milliliter can sells for 7.96 which size is better buy? what must she consider other than price?1 solutions Answer 190230 by richwmiller(9143)   on 2010-01-19 12:11:46 (Show Source): You can put this solution on YOUR website!396/237=1.67089 per ml 796/946=.841438 per ml about half the price
 Travel_Word_Problems/258414: Hello, This comes from Algebra and Trigonometry 4th edition book.I can't figure the formula needed when I don't have the speed of something already. A Leisure Time Cruise riverboat travels 46 km downstream in 2 hr. It travels 51 km upstream in 3 hr. Find the speed of the boat and the speed of the plane. Thank you for your help!1 solutions Answer 190228 by richwmiller(9143)   on 2010-01-19 12:03:45 (Show Source): You can put this solution on YOUR website!speed * time =distance also written as r*t=d We know the time and the distance Surely, if I told you that I went 60 miles in one hour you would say that I went 60 mph. x*1=60 x=60 or if I told you that I went 120 miles in 2 hours you would know I went 60 mph. x*2=120 x=60 again But something is wrong with your problem. It says"Find the speed of the boat and the speed of the plane. " There is no plane mentioned. r*2=46 r=? You can solve this! and the other r*3=51 r=51/3=? so it should current not plane the current is 3 20+3=23 20-3=17
 Linear_Algebra/258389: Determine the shortest distance from (9,5) to 5x + 3y =151 solutions Answer 190225 by richwmiller(9143)   on 2010-01-19 11:36:33 (Show Source): You can put this solution on YOUR website!I had to think a second about this one. They are asking for the equation that for the line which passes through (9,5) and is perpendicular to 5x + 3y =15. Then we need the intersection of the two lines and then the distance from the intersection to (9,5) so find the slope of 5x + 3y =15 3y=15-5x y=15/3-5x/3 m=-5/3 perpendicular slope would be 3/5 5=3/5(9)+b 25=27+5b -2=5b -2/5=b y=3/5x-2/5 5x + 3y =15 5y=3x-2 and 3x-2=5y 3x-5y=2 5x+3y=15 9x-15y=6 25x+15y=75 34x=81 x = 81/34, y = 35/34 (9,5) (81/34,35/34) a^2+b^2=c^2 sqrt((9-81/34)^2 +(5-35/34)^2)= 7.7 units Here are some other ways to do it. Some much shorter. http://www.worsleyschool.net/science/files/linepoint/distance.html
 Miscellaneous_Word_Problems/258393: There are five more children in Ms. Brown's class than in mr. whites room. Ten children move from ms. browns room to mr. whites room. Now there are twice as many children in mr whites room as in ms browns room. How many children were in Ms. Browns room before the move?1 solutions Answer 190222 by richwmiller(9143)   on 2010-01-19 11:16:52 (Show Source): You can put this solution on YOUR website!b=w+5 2*(b-10)=w+10 b=25 w=20
 Money_Word_Problems/258380: On the first day, Joe joined a secret club as its only member. Each day after that, one more member joined than on the previous day. What was the membership of the club after 40 days? ((( I did this: 40 multiplied by 2 ; because it says each day after one more member joined than on the previous. So then I got 80 and added joe and got 81???)))1 solutions Answer 190218 by richwmiller(9143)   on 2010-01-19 10:53:27 (Show Source): You can put this solution on YOUR website!day joined membership 0 0 0 1 1 1 2 2 3 3 3 6 4 4 10 5 5 15 6 6 21 7 7 28 8 8 36 9 9 45 10 10 55 11 11 66 12 12 78 13 13 91 The new total is the previous total plus the new day #8 is 36 which is 1/2*8*9 #10 is 55 which is 1/2*10*11=55 #12 78 1/2 12*13=6*13 total = day*day+1*1/2 It also works with odd numbers #11 11*12*1/2=66 so we have t=d*(d+1)*1/2 t=40*41*1/2 t=20*41=820 after 40 days
 Miscellaneous_Word_Problems/258375: During the first two weeks of the semester, 5 students withdrew from Hailey's Algebra class, 8 students were added to the class, and 4 students were dropped as "no shows". By how many students did the original class size change?1 solutions Answer 190215 by richwmiller(9143)   on 2010-01-19 10:31:24 (Show Source): You can put this solution on YOUR website!We jus t have to note the changes -5+8-4 =-9+8= =-1 There is one less on the books for the class than at the beginning. -5+8=+3 But since 4 never showed, there are three more in class than at the beginning