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# Recent problems solved by 'richwmiller'

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 Polynomials-and-rational-expressions/289566: Express the perimeter of the rectangle as a single rational expression given one side as X divided by X+5 and the other side as X divided by X+6 1 solutions Answer 209694 by richwmiller(9144)   on 2010-04-07 12:39:29 (Show Source): You can put this solution on YOUR website!2*(x/(x+5)+x/(x+6))
 Number-Line/289510: Define a variable and write an inequality. Then solve. A local summer baseball team plays 20 games each season. So far, They have won 9 games and lost 2.How many more games must they win this season to win at least 75% of all their games? I know the answer is 6 more games, but I need some help with graphing the problem.1 solutions Answer 209692 by richwmiller(9144)   on 2010-04-07 12:37:39 (Show Source): You can put this solution on YOUR website!Let x= number of games need to win to have 75% win (.75*20)-9=x The 2 games they lost is extra info meant to confuse the problem. Don't be confused
 Polynomials-and-rational-expressions/289506: how to solve rational expression 5/x^2+3x - 4/x^2-x-121 solutions Answer 209688 by richwmiller(9144)   on 2010-04-07 12:32:44 (Show Source): You can put this solution on YOUR website!Equations are solved. Expressions are simplified or reduced. Hint : x^2+3x=x*(x+3) x^2-x-12=(x+3)*(x-4) Result (x-20)/((x-4)* x* (x+3))
 Equations/289504: Solve: 8y^3 + 27 divided by 2xy - 10y + 3x -151 solutions Answer 209685 by richwmiller(9144)   on 2010-04-07 12:26:50 (Show Source): You can put this solution on YOUR website!Solve: 8y^3 + 27 divided by 2xy - 10y + 3x -15 This is not an equation and so can't be solved. It is an expression and can be reduced or simplified. 8y^3 + 27=(2y+3)*(4y^2-6y+9) 2xy - 10y + 3x -15=(x-5)*(2 y+3) (2y+3)*(4y^2-6y+9)/(x-5)*(2 y+3) (4y^2-6y+9)/(x-5) This is the furthest this can go since we have x in the denominator and and y in the numerator
 Linear-equations/289536: What is the equivalent to 3a + 4b - (-6a - 3b) and how do you get to the answer?1 solutions Answer 209670 by richwmiller(9144)   on 2010-04-07 10:56:19 (Show Source): You can put this solution on YOUR website!This is not a linear equation, slope nor graph problem. There are many equivalents not just "the" equivalent. An equivalent is 6a+8b-(-12a-6b) but I suspect that is not what you really meant to ask. multiply everything in the parentheses by -1 because 3a + 4b - (-6a - 3b) means 3a + 4b -1* (-6a - 3b) Work out (-1)*-6a)+(-1*)*(-3b) then add that to 3a+4b
 Linear-equations/289533: Write the equation of the line with slope -9 and y-intercept (0,4)1 solutions Answer 209667 by richwmiller(9144)   on 2010-04-07 10:11:40 (Show Source): You can put this solution on YOUR website!y=mx+b m is the slope b is the y intercept just plug them in
 Divisibility_and_Prime_Numbers/289532: What is the smallest number that should be added to 1000 so that 45 divides the sum exactly?1 solutions Answer 209666 by richwmiller(9144)   on 2010-04-07 10:07:13 (Show Source): You can put this solution on YOUR website! 1000/45 =22 2/9 22 2/9=22 10/45 so we need to add 35 1035/45=23
 test/289437: Sorry i don't know what is the topic to the question i am going to ask. But what is directly proportional? It appeared in my test serveral times but i don't understand.1 solutions Answer 209665 by richwmiller(9144)   on 2010-04-07 10:00:45 (Show Source): You can put this solution on YOUR website!"algebra proportions' seems a likely category. Repeating what the other tutor said if you work 8 hours for 10 dollars you will get 80 dollars 80=8*10 p=10*h pay = wage*hours y=kx Usually in those direct proportion problem you will be given a sample x and y so you can find k then they will either given you n x or y and want the other John worked 8 hours and earned \$64 the next day he earned \$72 how many hours did he work the second day inversely proportional y=k/x but that is another topic
 Trigonometry-basics/289521: prove that (sin^2)x(1+cot^2(x))=1. i don't have the slightest clue how to do this. please help. thanks1 solutions Answer 209658 by richwmiller(9144)   on 2010-04-07 09:29:02 (Show Source): You can put this solution on YOUR website!Just present the problem with a thank you. Telling us that you don't have the slightest clue doesn't help solve the problem. It just makes me wonder "Where was this person during class?" Everyone here really needs help. The key to this problem is trig identities. Gather up all the trig identities that you can find especially those with sin^2 and tangent ^2 or cotangent ^2 PS Don't use x for multiplication when you also use x for an unknown. http://www.sosmath.com/trig/Trig5/trig5/trig5.html
 Linear-equations/289522: If x = -3, what is the value of: X2 - 1 (the X2 is squared) ______ X + 11 solutions Answer 209655 by richwmiller(9144)   on 2010-04-07 09:13:30 (Show Source): You can put this solution on YOUR website! plug in -3 for x
 Linear-equations/289389: the problem is 4x-6y=5and 2x-3y=7 am I suppose to multiple the top by a number 1 solutions Answer 209635 by richwmiller(9144)   on 2010-04-06 23:43:09 (Show Source): You can put this solution on YOUR website!4x-6y=5and 2x-3y=7 You haven't told us what you are trying to do. 4x-6y=5 2x-3y=7 But you may notice that they have the same slope and so they are parallel and never intersect and therefore have no "solution" -a/b= slope -4/-6=2/3 -2/-3=2/3
 Graphs/289429: a car leaves town and drives east at 50 miles per hour. a second car leaves the same point three hours later and also drives north at 50 miles per hour. how far apart are they 4 hours after the second care leaves?1 solutions Answer 209630 by richwmiller(9144)   on 2010-04-06 23:34:59 (Show Source): You can put this solution on YOUR website!The first car went 3*50=150 miles before the second car left after 4 more hours they each go 200 miles. So the first car has gone 350 and the second car 200 the distance between them d=sqrt(350^2+200^2)=50sqrt(65)=403.11
 Money_Word_Problems/289430: How do you find compound interest?1 solutions Answer 209629 by richwmiller(9144)   on 2010-04-06 23:29:27 (Show Source): You can put this solution on YOUR website!You go to a bank and ask politely.
 Inequalities/289405: how can you quickly solve for a boundary point? and what is the boundary point for 3-2x<1?1 solutions Answer 209628 by richwmiller(9144)   on 2010-04-06 23:27:59 (Show Source): You can put this solution on YOUR website!Since there are two questions, I will only answer the first. I can solve them very fast. Did you see me do it? Ok. Watch closely. I am going to do it again. Did you see me? Based on that, I will leave the second question for you to solve.
 Rectangles/289426: How would I figure out the rectangle that was 7/8yards by 32/49 yards? And then put it into sq ft. Thank you1 solutions Answer 209627 by richwmiller(9144)   on 2010-04-06 23:23:16 (Show Source): You can put this solution on YOUR website!change yards to feet first (7/8)*3 and (32/49)*3 You didn't say what you mean by "figure out" But you mentioned sq feet which is area. 36/7=5.14 sq ft
 Pythagorean-theorem/289394: How do i set this problem up for the pythagorean theorem? 1/3, 2 with the square root of 2/3, and 1?1 solutions Answer 209625 by richwmiller(9144)   on 2010-04-06 23:16:46 (Show Source): You can put this solution on YOUR website!What does this mean? 2 with the square root of 2/3 The largest will be c and the other two a and b. It doesn't matter which is a and which is b a^2+b^2=c^2
 Quadratic_Equations/289339: 11>5-2x > or = -71 solutions Answer 209623 by richwmiller(9144)   on 2010-04-06 22:58:35 (Show Source): You can put this solution on YOUR website!11>5-2x>=-7 6>-2x>-12 We are going to divide by -2 which means we flip the signs 6/-2>x>6 -3>x>=6 now flip the signs -3 done
 Numbers_Word_Problems/289409: Use two equations with two variables to solve the problem. The sum of two numbers is 15 less than twice the first number. Their difference is 5 less than twice the second number. Find each of the numbers. I appreciate any help that can get me to see the equation and the solution. Thank you so much Sharon1 solutions Answer 209612 by richwmiller(9144)   on 2010-04-06 22:02:04 (Show Source): You can put this solution on YOUR website!sum means we are going to add things less means we are subtracting something is means equals twice means two times difference means subtraction x+y=-15+2x or x+y=2x-15 Now the second sentence x-y=-5+2x or x-y=2x-5 #1 x+y=2x-15 #2 x-y=2x-5 combine y=x-15 -y=x-5 add 0=2x-20 20=2x x=10 10-5=-y 5=-y y=-5 (10,-5) #1 x+y=2x-15 10-5=20-15 5=5 #2 x-y=2x-5 10-(-5)=2*(10)-5 15=20-5 15=15 ok
 Graphs/289397: What is the x-coordinate of the solution to the system of linear equations below? 4x + 5y = 8 2x - 3y = -18 is this right? 2x + 2y = 10 troykoen@gmail.com1 solutions Answer 209610 by richwmiller(9144)   on 2010-04-06 21:50:46 (Show Source): You can put this solution on YOUR website!The x coordinate will be a number of some sort. It might be a whole number, a fraction or a decimal. In this case x=-3
 logarithm/289247: I am trying to solve this exponent equation: 3^2-x^2=8 the whole exponent is 2-x^2. I have the answer of + or - .3274, but would like to see the solution outlined. Thank you.1 solutions Answer 209606 by richwmiller(9144)   on 2010-04-06 21:33:21 (Show Source): You can put this solution on YOUR website!I think the other tutor misread the problem. 3^(2-x^2)=8 3^2*3^(-x^2)=8 9*3^(-x^2)=8 1/(3^(x^2))=8/9 3^(x^2)=9/8 x=-sqrt((log(9/8))/(log(3))) x=-0.327431 x=sqrt((log(9/8))/(log(3))) x=0.327431 = your answer
 Miscellaneous_Word_Problems/289380: at work one day erica received 36 packages. Speedy delivery delivered three times as many as ralphs express, While ralphs express delivered four more packages the sendquick package service. how many packages did each service deliver to erica?1 solutions Answer 209602 by richwmiller(9144)   on 2010-04-06 21:09:48 (Show Source): You can put this solution on YOUR website!s=3r r=q+4 q=r-4 r+s+q=36 r+3r+r-4=36 5r-4=36 5r=40 r=8 q = 4, r = 8, s = 24
 Exponents/289325: Hey guys. Recently in a maths textbook I read something along the lines of (xy)^3 (can't figure out how to write it so that it comes up like a power, sorry). The answer, much to my disbelief, the answer was xy^3 (as I understand it should have been x^3y^3). I wrote it off as an error in the answering sheet (something that happens somewhat often) and moved on. Now, however, I've come to an example further in the book of a question written: {(ab)^2}^-4 it then continues: (ab^2)^-4 = a^-4 b^2*-4 = a^-4 b^-8 = 1/(a^4b^8) This is confusing me beyond comprehension; how is {(ab)^2}^-4 equal to (ab^2)^-4? Is it equal, or have they made yet another stuff up? Normally I'd think my previous teacher taught me wrong faced with so much evidence, but I simply can't find any consistency, everything in the brackets is raised to the -4, why not the 2? Combined with the fact that this book has had three things in a row wrong before, I'm inclined to believe who ever wrote it was either tired or drunk. My thanks; Matt.1 solutions Answer 209601 by richwmiller(9144)   on 2010-04-06 21:00:29 (Show Source): You can put this solution on YOUR website!Were these gaffs in the answer section in the back of the book? Textbooks are famous for changing the problems but not changing the answers.
 Polynomials-and-rational-expressions/289359: When adding polynomials, do i add the exponents together also: ex:(x^2+x+1)+(2x-9x^2)=? my answer was: 3x^3-5x^2-5x1 solutions Answer 209599 by richwmiller(9144)   on 2010-04-06 20:49:27 (Show Source): You can put this solution on YOUR website!not even close. You add the terms with like exponents. So 7a^2-3a^2=4a^2
 Finance/289364: I am needing help solving this word problem- these are too confusing to me The total profit (in dollars) for sales of x rowing machines is given by P(x)= -0.2^2 + 300x -200. What is the profit if 500 are sold? For what value of x will the profit be a at maximum? Thanks, Jen1 solutions Answer 209595 by richwmiller(9144)   on 2010-04-06 20:27:39 (Show Source): You can put this solution on YOUR website!Check you equation. There is something missing. Probably an x in the term -0.2^2 It should probably be -0.2x^2 Otherwise it is a straight line. so when you get the right equation, you should find the vertex. -b/2a here b is 300 a=-.2
 Linear-equations/289360: Provide 3 coordinate points that would lie on the line x=7. Explain in your own words what the line x=7 would look like if it were graphed, and explain how do you know? 1 solutions Answer 209593 by richwmiller(9144)   on 2010-04-06 20:22:58 (Show Source): You can put this solution on YOUR website!x=7 is a vertical line. Y changes but x never changes. So just pick any three numbers for y and match them up with (7, ) (7, ) (7, )
 Linear-equations/289350: I'm not sure how to do this one... I'm sure there's a certain "formula" but I don't know it. Write an equation for the line parallel to the line 4x=-3 through the point (4,-3).1 solutions Answer 209592 by richwmiller(9144)   on 2010-04-06 20:20:10 (Show Source): You can put this solution on YOUR website!Actually, it is easier than you think. You just have to know stuff. 4x=-3 is a vertical line So your equation will be of the form x=? We want the line to pass through 4,-3 So x=4 y=-3 And the equation is x=4 All done
 Geometry_Word_Problems/289356: How do I go about solving this? a bicycle tire is 2 ft in diameter. How many turns will the tire make if it travels exactly one mile (5,280 ft).1 solutions Answer 209591 by richwmiller(9144)   on 2010-04-06 20:15:49 (Show Source): You can put this solution on YOUR website!find the circumference of the tire. c=2*pi*r pi is abt 3.14 find the radius=r=diameter/2 5280/(2*pi*r)=turns
 Rate-of-work-word-problems/289349: You are the parent of busy children and have a parent teacher conference in one hour; you know that it takes 10 minutes for the cold water to fill the tub and 12 minutes for the hot water to fill the tub. How long will it take to fill the tub if both faucets are open1 solutions Answer 209590 by richwmiller(9144)   on 2010-04-06 20:13:13 (Show Source): You can put this solution on YOUR website!x/10+x/12=1 12x+10x=120 22x=120 11x=60 x=60/11=5 5/11 minutes 5*60/11 300/11=27 second 5 minutes and 27 seconds together check 60/11/10=6/11 for the cold water 60/11/12=5/11 for the hot water 6/11+5/11=1 ok
 Linear-systems/289238: Dear Professor, i would very much appreciate it if you could help me solve the following algebra problem. thanks solve the system of equations,using substitiution or eliminationor back-substitution etc. x+3y-z=13 2x -5z=23 4x-y-2z=41 solutions Answer 209569 by richwmiller(9144)   on 2010-04-06 16:54:16 (Show Source): You can put this solution on YOUR website!x = -12/17, y = 50/17, z = -83/17 x+3y-z=13 2x -5z=23 4x-y-2z=4 multiply the first by -2 -2x-6y+2z=-26 4x-y-2z=4 add 2x-7y=-22 multiply #1 by 5 5x+15y-5z=65 2x -5z=23 subtract 3x+15y=42 divide by 3 x+5y=14 2x-7y=-22 #1 by 2 2x+10y=28 2x-7y=-22 subtract 17y=50 y=50/17 2x-7y=-22 2x-7*50/17=-22 x-7*25/17=-11 x=-12/17 2x -5z=23 2*(-12/17)-5z=23 -24/17-5z=23*17/17 z=-83/17
 Circles/289235: A baseball has the radius of 1.5". Home plate is 16 inches wide. If the baseball rolled across home plate, how many complete rotations would it take to cover the distance?1 solutions Answer 209565 by richwmiller(9144)   on 2010-04-06 16:40:49 (Show Source): You can put this solution on YOUR website!circumference =2*pi*r 6.28*1.5 16/(2*3.14*1.5) 8/3.14*1.5 almost 4 times 3.82 times across the width of a 16 in homeplate
 Finance/289228: at 7:00 a.m joe starts jogging at 6 mi/h. at 7:30 ken starts off after him. how fast must ken run in order to overtake him at 7:30 a.m.? 1 solutions Answer 209563 by richwmiller(9144)   on 2010-04-06 16:36:11 (Show Source): You can put this solution on YOUR website!sorry but you input both times for ken as 7:30 am