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Recent problems solved by 'richwmiller'

richwmiller answered: 9124 problems
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Linear-systems/280114: in 1992 life expectancy was 63.4. in 1998 it was 67.0 E= life expectanc in year t and let t = # of years since 1992 what is the linear function for this? what would the life expectancy be if E(16) 1 solutions Answer 203575 by richwmiller(9135)   on 2010-03-12 12:25:25 (Show Source): You can put this solution on YOUR website! your points are (0, 63.4) and (6,67) use them to write an equation after finding m and b y-y/x-x=m then find b using y=mx+b now that you have m and b plug them in y=mx+b where y=E(x)

Rational-functions/280127: use synthetic division to divide x^4+4x^3+6x^2+4x+1 by x+1 how do i figure this. thanks 1 solutions Answer 203574 by richwmiller(9135)   on 2010-03-12 12:21:01 (Show Source): You can put this solution on YOUR website! Do you have any notion what synthetic division is? http://www.purplemath.com/modules/synthdiv.htm

Linear-systems/280129: Solve this system: y=5x-1 and y=8x+4 1 solutions Answer 203573 by richwmiller(9135)   on 2010-03-12 12:19:04 (Show Source): You can put this solution on YOUR website! set them equal and solve for x 5x-1=8x+4

Rational-functions/280130: solve x^3+2x^2+x+2=0 if -2 is a root. how is this done im not sure 1 solutions Answer 203572 by richwmiller(9135)   on 2010-03-12 12:15:47 (Show Source): You can put this solution on YOUR website! plug -2 in for x and calculate

Travel_Word_Problems/280126: if you are traveling 2430 feet per second how fast are you going in MPH? 1 solutions Answer 203571 by richwmiller(9135)   on 2010-03-12 12:14:36 (Show Source): You can put this solution on YOUR website! 5280 ft= 1 mile 360 sec = 1 hour 60 seconds= 1 minute 60 minutes = 1 hour

Travel_Word_Problems/280124: Selling shirts... If a vendor charges p dollars for rugby shirts, then he expects to sell 2000 - 100 shirts at a tournament. Write and solve an equation using the word problem above. 1 solutions Answer 203569 by richwmiller(9135)   on 2010-03-12 12:11:39 (Show Source): You can put this solution on YOUR website! What makes you think this problem is related to travel and distance?

Proportions/280120: on each field how much playing area is outside indicated part. round to nearest whole number if necissary. 1. a professional basket ball court, outside the 2 rectangular free throw lanes, ea 19ft by 14ft there is a graph of a proffessional basketball court in book, i dont know if I use this in figuring. can you help me please?? the graph is length 94ft, width 50ft and we had to find area, which is 4700ft 1 solutions Answer 203568 by richwmiller(9135)   on 2010-03-12 12:09:39 (Show Source): You can put this solution on YOUR website! The graph is there for decoration and to fill the book. It is there to confuse the student with facts. It certainly shouldn't be used by students. As a matter of fact the whole book is full of facts and should be ignored by students and basketball players. 94*50-2*(19*14)=4168

Linear-systems/280111: x+9y =2 (1) x= 8-9y (2) 1 solutions Answer 203563 by richwmiller(9135)   on 2010-03-12 11:35:51 (Show Source): You can put this solution on YOUR website! x+9y =2 x= 8-9y 8-9y+9y=2 8=2 the lines do not cross 9y=2-x y=2/9-x/9 y=-x/9+2/9 x=8-9y 9y=8-x y=8/9-x/ y=-x/9+8/9 the lines are parallel

Linear-equations/280009: How do I solve the system using addition/elimination method and show work? 3x+2y=14 3x-2y+10 1 solutions Answer 203558 by richwmiller(9135)   on 2010-03-12 11:08:50 (Show Source): You can put this solution on YOUR website! assuming you mean 3x-2y=10 3x+2y=14 add 6x=24 x=4 3*4-2y=10 12-2y=10 -2y=-2 y=1 (4,1)

Surface-area/280116: Solve by factoring: A rectangular painting with a width of x centimeters has an area of x^+50x square centimeters. Find a binomial that represents the length. 1 solutions Answer 203553 by richwmiller(9135)   on 2010-03-12 10:59:07 (Show Source): You can put this solution on YOUR website! assuming you mean the area is x^2+50x L*W=x^2+50x L*x=x*(x+50) L=x+50

Linear_Equations_And_Systems_Word_Problems/280112: The Brooklyn Bridge was built 54 years before the Golden Gate Bridge. In 1983 the Golden Gate Bridge was 23/50 the age of the Brooklyn Bridge. What year was each bridge built? 1 solutions Answer 203549 by richwmiller(9135)   on 2010-03-12 10:55:31 (Show Source): You can put this solution on YOUR website! b-g=54 23/50*b=g b-23b/50=54 b=100 BB was built in 1883 1883+54=g 1937=g GGB was built in 1937

Geometry_Word_Problems/280079: The length, L, of a rectangle is increased by 50% and the width, W, is doubled to form a larger rectangle with an area of 30 cm2. What is the largest possible perimeter of the larger rectangle if L and W are integers with L > W? 1 solutions Answer 203540 by richwmiller(9135)   on 2010-03-12 10:36:33 (Show Source): You can put this solution on YOUR website! 1.50L*2w=30 l>w original length and width are (5 and 2) or (10 and 1) testing 5 and 2 7.5 and 4 7.5*2+2*4=15+8=23 cm perimeter and 10 and 1 15 and 2 15*2+2*2=34 cm perimeter 34> 23 so 34 cm is the largest possible perimeter with integer sides in the original.

Word_Problems_With_Coins/280107: Betty has 10 more dimes than quarters. If she has $3.45, how many coins does she have? 1 solutions Answer 203536 by richwmiller(9135)   on 2010-03-12 10:23:56 (Show Source): You can put this solution on YOUR website! d=q+10 10d+25q=345 d=17 q=7 check 170+175=345 345=345 ok d+q=24 coins

Inequalities/280108: show that the values 0,1,-1 for x all satisfy (x-1)(x-1)+(x+1)(x+1)=2(x*x+1). Is this equation an identity? 1 solutions Answer 203534 by richwmiller(9135)   on 2010-03-12 10:19:32 (Show Source): You can put this solution on YOUR website! using foil (x-1)*(x-1) x^2-2x+1 (x+1)*(x+1) x^2+2x+1 adding together 2x^2-2x+2x+1+1 2x^2+2 2(x^2+1) 2(x*x+1)

Volume/280105: how many gallons of water will fill a fish tank that is 10 in. long, 6 in. wide, and 7 in high 1 solutions Answer 203531 by richwmiller(9135)   on 2010-03-12 10:10:34 (Show Source): You can put this solution on YOUR website! v=l*w*h v=10*6*7 v=420 in^3 now convert cubic inches to gallons 231 cubic inches =1 gallon I'll leave that for you 420/231

Linear-equations/280106: find slope and y intercept f(x)= -9x-10 1 solutions Answer 203528 by richwmiller(9135)   on 2010-03-12 10:07:21 (Show Source): You can put this solution on YOUR website! slope is -9 and y intercept is -10

Equations/280103: There are 480 dishes that need to be rinsed. John can rinse them in 80 minutes by himself. It will take his friend Bob 120 minutes to rinse these dishes. How long will it take them if they rinse these 480 dishes together? 1 solutions Answer 203524 by richwmiller(9135)   on 2010-03-12 10:04:22 (Show Source): You can put this solution on YOUR website! We have to assume there are two places with easy access to the same dishes and the two workers don't get in each other's way. Even 80 minutes seem to be excessively long to rinse dishes. We are not talking about washing them but just rinsing them. x/80+x/120=1 3x+2x=240 5x=240 x=240/5 x=48 minutes together another interesting way to calculate using the 480 dishes in 1 minute john can do 480/80=6 dishes in 1 minute bob can do 480/120=4 dishes 4x+6x=480 10x=480 x=48 minutes

Percentage-and-ratio-word-problems/279975: An instrument store gives a 10% discount to all students off the original cost of an instrument. During a back to school sale an additional 15% is taken off the discounted price. Julie, a student at the local high school, purchases a flute for $306. How much did it originally cost? 1 solutions Answer 203520 by richwmiller(9135)   on 2010-03-12 09:53:29 (Show Source): You can put this solution on YOUR website! x= original cost .9*x= discounted price .85*(.9x)= final price .85*.9x=306 .765x=306 x=400 note if the 10% and 15% were added together it would be .75x=306 x=408

Travel_Word_Problems/280084: 3 cars drive 300 miles on a striaght road in the Arizona desert. Car A excellerates to 50 miles an hour and keeps this speed constantly. Car B excellerates to 60 miles an hour and keeps this speed constantly but stops twice for 30 mins. Car C excellerates to 75 miles an hour and keeps this speed constantly but stops once for 2 hours. QUESTION ..... What order do the 3 cars finish the 300 mile drive? 1 solutions Answer 203517 by richwmiller(9135)   on 2010-03-12 09:43:40 (Show Source): You can put this solution on YOUR website! No idea what "excellerates" means. It is not a word. BTW neither is "striaght" Perhaps you mean "accelerates" and "straight" We are not told if the cars start at the same time or one hour after the other. car A 50x=300 x=6 hrs Car B 60x=300 x=5 hrs +2*30 mins =6 hrs Car C 75x=300 x=4 hrs+ 2 hr=6 hrs They all arrive at the same time. or Car A arrives first because it didn't have to keep accelerating.

Percentage-and-ratio-word-problems/271068: A local country club has a membership of 600 and operates facilities that include an 18-hole championship golf course and 12 tennis courts. Before deciding whether to accept new members, the club president would like to know how many members regularly use each facility. A survey of the membership indicates that 65% regularly use the golf course, 49% regularly use the tennis courts, and 7% use neither of these facilities regularly. What is the probability that a worker regularly uses both golf and tennis facilities? A. .49 B. .21 C. .70 D. .93 1 solutions Answer 203516 by richwmiller(9135)   on 2010-03-12 09:31:29 (Show Source): You can put this solution on YOUR website! You jumped from talking about members to asking about workers! We know nothing about worker privileges nor habits.

Polynomials-and-rational-expressions/280096: Here is a question from Algebra 1 "One city contains 22,000 elevators. If 2,000 more are for freight than for passengers, how many freight elevators are there?" 1 solutions Answer 203512 by richwmiller(9135)   on 2010-03-12 09:03:52 (Show Source): You can put this solution on YOUR website! two ways to solve this 22000-2000=20000 20000/2=10000 10000+2000=12000 freight elevators p+f=22000 f=p+2000 p+p+2000=22000 2p=20000 p=10000 f=12000

Word_Problems_With_Coins/280095: The coin box of a vending machine contains 6 times as many quarters as dimes. If the total amount of money in quarters and dimes is $28.80, how many quarters and how many dimes are in the box? 1 solutions Answer 203510 by richwmiller(9135)   on 2010-03-12 09:00:14 (Show Source): You can put this solution on YOUR website! 25q+10d=2880 6d=q 25*(6d)+10d=2880 160d=2880 16d=288 8d=144 d=18 6*d=q q=6*18 q=108 d=18 check 25*108+10*18=2880

Expressions-with-variables/280086: solve by elimination 5r-3s=1 3r+5s=21 1 solutions Answer 203509 by richwmiller(9135)   on 2010-03-12 08:54:32 (Show Source): You can put this solution on YOUR website! multiply the first by 5 and the second by 3 25r-15s=5 9r+15s=63 add 34r=68 r=2 5*2-3s=1 10-3s=1 9=3s 3=s r=2 3=s

Volume/280090: Which unit would be the most appropriate for expressing the volume of a swimming pool? 1 solutions Answer 203507 by richwmiller(9135)   on 2010-03-12 08:51:10 (Show Source): You can put this solution on YOUR website! either gallons or liters or cubic feet or cubic yards or cubic meters

Surface-area/280093: What is the height of a box with a length of 3 feet, a width of 2 feet and a surface area of 52 square feet? 1 solutions Answer 203506 by richwmiller(9135)   on 2010-03-12 08:48:57 (Show Source): You can put this solution on YOUR website! surface area of a rectangular box There are six sides 2 with length and width ie top and bottom 2*(3*2)=12 2 with length and height ie sides 2*(3*h)=6h 2 with width and height ie the ends 2*(2*h)=4h 12+6h+4h=52 10h=40 h=4 height = 4 feet check 12+24+16=52 52=52 ok

Geometry_Word_Problems/280083: A man has a 50-foot roll of fencing to make a rectangular shaped kennel. If he wants the kennel to be 6 feet longer than it is wide, the dimensions must be: (A) 3.5 ft x 9.5 ft (B) 11 ft x 17 ft (C) 9.5 ft x 15.5 ft (D) 5 ft x 11 ft (E) none of these 1 solutions Answer 203505 by richwmiller(9135)   on 2010-03-12 08:41:40 (Show Source): You can put this solution on YOUR website! 2L+2W=p L=W+6 2(W+6)+2W=50 2W+12+2W=50 4W+12=50 4W=38 2W=19 W=9.5 L=W+6 L=15.5 (C) 9.5 by 15.5

Complex_Numbers/279965: Given complex numbers u = 3/2 - 2i and v = 5/3 + 3i Compute the combination u + v 1 solutions Answer 203452 by richwmiller(9135)   on 2010-03-11 21:31:17 (Show Source): You can put this solution on YOUR website! u = 3/2 - 2i and v = 5/3 + 3i u +v= 3/2 - 2i + 5/3 + 3i u+v = 9/6 - 2i +10/6 + 3i 19/6+i 3 1/6+i

Graphs/279932: Can you determine what the graph of any function looks like just by looking at the function? We've been doing polynomial and rational (polynomial divided by polynomial) functions, and using the standard procedure for analyzing these functions (i.e. determining the vertical and/or horizontal asymptotes, y-int, x-int, etc.). We haven't done enough of these yet for me to determine what the graph may look like just by looking at it. Maybe seeing how the signs of the terms change, the relative size of the coefficients, the order (power) of the function, or some other property of the function, would allow me to sketch the graph of it without going through the trouble of substituting in points. Often, experienced scholars in a subject can do things like this, but I was wondering if there are tricks or tips for doing this. Thanks! By the way, we haven't done calculus yet, so we don't get to use calculus to figure out how to graph these functions. 1 solutions Answer 203443 by richwmiller(9135)   on 2010-03-11 20:47:13 (Show Source): You can put this solution on YOUR website! If by "looks like" you just mean the general shape. Hyperbola parabola ellipse, line, circle. yes there are standard formulas(equations) for those shapes.

Age_Word_Problems/279943: jon is 13 years older than tony. the sum of their ages is 27. how old are they? 1 solutions Answer 203442 by richwmiller(9135)   on 2010-03-11 20:44:08 (Show Source): You can put this solution on YOUR website! a sneaky way 27-13=14 14/2=7 7+13=20 20+7=27 7 and 20 are the ages Why does this work? another way. j=t+13 j+t=27 j-t=13 add 2j=40 j=20 27-20=7=t

Quadratic_Equations/279940: Solve by any method 4x2 – 7x + 5 = 0 1 solutions Answer 203440 by richwmiller(9135)   on 2010-03-11 20:39:50 (Show Source): You can put this solution on YOUR website! Solved by pluggable solver: SOLVE quadratic equation with variable Quadratic equation (in our case ) has the following solutons: For these solutions to exist, the discriminant should not be a negative number. First, we need to compute the discriminant : . The discriminant -31 is less than zero. That means that there are no solutions among real numbers. If you are a student of advanced school algebra and are aware about imaginary numbers, read on. In the field of imaginary numbers, the square root of -31 is + or - . The solution is Here's your graph:

Numbers_Word_Problems/279928: The sum of three consecutive even integers is 9,000. What is the largest of these integers? 1 solutions Answer 203437 by richwmiller(9135)   on 2010-03-11 20:37:02 (Show Source): You can put this solution on YOUR website! n-2+n+n+2=9000 3n=9000 n=3000 n-2=2998 n+2=3002 the largest is 3002