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# Recent problems solved by 'MRperkins'

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 Proofs/687765: Hello I am supposed to symbolize English arguments using the schemes and abbreviations provided and then construct proofs to show that the arguments are valid. This one is: Either we should stop going places, or we should develop hydrogen-powered cars, or we should go on driving gasoline-powered cars. We should go on driving gasoline-powered cars only if we should destroy the ozone layer. We should not stop going places and we should not destroy the ozone layer. Therefore, we should develop hydrogen-powered cars. (P: We should stop going places; H: We should develop hydrogen-powered cars; G: We should go on driving gasoline powered cars;O: We should destroy the ozone layer) So far I just tried to construct the abbreviation, but I don't feel like it fits with the forms. I have: Pv(HvG) G<->O P.o H And on top of that I am really not understanding how to formulate proofs for my class. I thought I was grasping it really well up until now. Any help would be appreciated. Walking me through the problem would be amazing.1 solutions Answer 425332 by MRperkins(300)   on 2012-11-30 21:52:34 (Show Source): You can put this solution on YOUR website!I would love to talk to you about this one go to http://www.scribblar.com/mg9yqg9 to get my email address. You are missing the negation symbols like for stop going places would be -g where - is the negation symbol. email me and we will talk
 Quadratic_Equations/687718: Find the equation of the parabola that passes through the points (2,3) and (10,3) and has a max value of y=35. Can you please help me out? thanks in advance1 solutions Answer 425322 by MRperkins(300)   on 2012-11-30 21:16:44 (Show Source): You can put this solution on YOUR website!email me and I will work this one out with you in an online whiteboard. http://www.scribblar.com/mg9yqg9 Basically, we are dealing with a quadratic function. Generally, that will involve using the "vertex form" so, we know that there is a maximum of y=35. what, in the formula, is the y value of the vertex of the parabola? (b) Since the y values are the same on the given points, then the axis of symmetry is in the middle of them (2+10)/2 or 6. that is the h value of the vertex. If they were not the same y values, then we could still find the h value, but it would be more complicated: . . ***alternative way to find h value Start*** . so we can insert that into the formula: y=a(x-h)^2+35 we also know two points that work. enter the first point and you get 3=a(2-h)^2+35 foil (2-h)^2 to get h^2-4h+4, solve for "a" a=-32/(h^2-4h+4) . now plug the other point into y=a(x-h)^2+35 and you get 3=a(10-h)^2+35 subtract 35 from both sides -32=a(10-h)^2 substitute -32/(h^2-4h+4) from the first equation in for a in the second equation. You get: -32=(-32(10-h)^2)/(h^2-4h+4) reduce the -32's and move the h^2-4h+4 to the left reduce to find the h value. h=6 ***alternative way to find h value Stop*** . . so now you have y=a(x-6)^2+35 use one of the points for the x and y value to find "a" 3=a(4)^2+35 -32/16=a a=-2 so y=-2(x-6)^2+35
 test/687735: could you guys help me with my algebra 2 math problems1 solutions Answer 425302 by MRperkins(300)   on 2012-11-30 20:41:10 (Show Source): You can put this solution on YOUR website!http://www.scribblar.com/mg9yqg9 send me an email and I will send you a link to a whiteboard.
 Polynomials-and-rational-expressions/687732: what is b^2-18b+801 solutions Answer 425301 by MRperkins(300)   on 2012-11-30 20:39:52 (Show Source): You can put this solution on YOUR website!I am guessing that you want to find the zeros or how to factor it. It factors to (b-10)(b-8) If you want to ask more specific questions, then get my email address from http://www.scribblar.com/mg9yqg9 and ask away.
 Linear-systems/687688: Is c=0.05m+20 a linear equation?1 solutions Answer 425284 by MRperkins(300)   on 2012-11-30 19:22:05 (Show Source): You can put this solution on YOUR website!Yes, it is a linear equation. If this is not what you intended to ask, then go to http://www.scribblar.com/mg9yqg9 to get my email address.
 Radicals/687540: the square root of 1/361 solutions Answer 425194 by MRperkins(300)   on 2012-11-30 11:25:05 (Show Source): You can put this solution on YOUR website!square root the top and the bottom
 logarithm/687545: log(x+9)-logx=31 solutions Answer 425192 by MRperkins(300)   on 2012-11-30 11:22:45 (Show Source): You can put this solution on YOUR website!Combine the two logarithms into a single logarithm log[(x+9)/x]=3 rewrite in exponential form solve for x 1000x=x+9 999x=9 Verify this in your calculator by substituting 1/111 in for x. Let me know if you have any other questions. Justin
 Linear_Algebra/687524: How do I write this in a system? The larger of two numbers is 6 less than 3 times the smaller number. I need to have two variables. So I think it is x=3y-6. Did I do that right?1 solutions Answer 425187 by MRperkins(300)   on 2012-11-30 10:43:54 (Show Source): You can put this solution on YOUR website!yes, but "systems" usually contain 2 or more equations. Is there more to the problem or do you just have to write an equation? Also, you might identify your variables and say that x is your larger number and y is the smaller number. Do you know what the 2 numbers sum is or anything else? If so, then you could write another equation and then solve the system. You can get my email address to contact me at: http://www.scribblar.com/mg9yqg9
 Word_Problems_With_Coins/687517: Aubrey has \$4.00 of quarters and nickels in her coin purse. She has 3 times as many quarters as she does nickels. How many quarters and nickels does she have? X=quarters Y=nickels I know how to solve. I just don't know how to set up the two equations.. I can use elmination or substitution. 1 solutions Answer 425183 by MRperkins(300)   on 2012-11-30 10:28:00 (Show Source): You can put this solution on YOUR website!Let q be the number of quarters and n be the number of nickels. The most important thing here is to understand that q is the NUMBER of nickels, not how much they are worth (same with q and quarters). so, .25q+.05n=4 now we need to look at the relationship of quarters to nickels. It is tricky sometimes to write this part, is it 3n=q or 3q=n??? I read this as she has more quarters than nickels, (3 times as many to be exact). So which one would make the number of quarters larger than the number of nickels? 3n=q I would use substitution at this point. You can get my contact information at: http://www.scribblar.com/mg9yqg9
 logarithm/687515: Solve: log base 5 (3x-1) - log base 5 (x+5)= 01 solutions Answer 425182 by MRperkins(300)   on 2012-11-30 10:13:46 (Show Source): You can put this solution on YOUR website!using the subtraction property of logarithms, we can combine the two logarithms and get log base 5 [(3x-1)/(x+5)]=0 Then, we can rewrite the problem in exponential form. I always say "a to the b equals c" for a general exponential form and then drop the a down to the base, move the "b" to the right side of the equals sign, and then move the c to the left. It looks something like this: Exponential form: Logarithm form: log base a of c=b So, in this case, our "a" is 5, our "b" is 0 and our "c" is and we can write it in exponential form: well, because of the zero exponent property and therefore Multiply both sides by (x+5) and then solve for x You can find my contact information at: http://www.scribblar.com/mg9yqg9 if you need additional help.
 Functions/499798: find the range of the function: f(x) = 3x-5. with domain (-1,4]1 solutions Answer 337862 by MRperkins(300)   on 2011-09-18 15:12:09 (Show Source): You can put this solution on YOUR website!The range (possible y values) is (-8,7]
 Functions/499794: solve x^4*sqrtx and what is the domain? Answer?? x^9/21 solutions Answer 337861 by MRperkins(300)   on 2011-09-18 15:10:25 (Show Source): You can put this solution on YOUR website!You are correct. rewrite sqrt(x) as x^(1/2) and then when you multiply like bases, we add the exponents, so we get 4+1/2=9/2 the domain is because you can not get a real answer by taking the square root of a negative number.
 Systems-of-equations/499774: solve by addition 8x=-11y-16; 2x+3y=-41 solutions Answer 337854 by MRperkins(300)   on 2011-09-18 15:02:35 (Show Source): You can put this solution on YOUR website!I can help at http://www.scribblar.com/whh9htqcx This is a free browser based online whiteboard. The answer is (-2,0), but I will show the work at the above link.
 Triangles/499782: if xy = 10 and xw = 12, what is vy?1 solutions Answer 337853 by MRperkins(300)   on 2011-09-18 14:57:00 (Show Source): You can put this solution on YOUR website!I think you have something written wrong, we know nothing about v
 expressions/499779: -8 + (-3)1 solutions Answer 337852 by MRperkins(300)   on 2011-09-18 14:53:09 (Show Source): You can put this solution on YOUR website!-11
 Human-and-algebraic-language/499764: TRANSLATE AND SIMPLIFY VERBAL EXPRESSION A NUMBER A SUBTRACTED FROM THE PRODUCT OF THE NUMBER AND SEVENTEEN1 solutions Answer 337845 by MRperkins(300)   on 2011-09-18 14:36:12 (Show Source): You can put this solution on YOUR website!17a-a simplifies to: 16a
 Triangles/499758: The perimeter of an equilateral triangle is 7 inches more than the perimeter of a square, and the side of the triangle is 5 inches longer than the side of the square. Find the side of the square.1 solutions Answer 337840 by MRperkins(300)   on 2011-09-18 14:21:44 (Show Source): You can put this solution on YOUR website!Let the Perimeter of the square be P=4s Then the Perimeter of the triangle is P+7=3(s+5) Substitute 4s+7=3(s+5) 4s+7=3s+15 s=8 Here is an online whiteboard that I use while I am working problems on algebra.com. Although you can access it anytime, I only monitor it while I am working problems. http://www.scribblar.com/whh9htqcx I am working on your problem right now and will update this answer within the next 5-15 minutes, but if you want to see additional information or talk to me while I work it out, then go to the link above.
 Linear-equations/499753: find the slope of each line whose equation is giving. if the slope is undefined, state this. y=-41 solutions Answer 337839 by MRperkins(300)   on 2011-09-18 14:17:04 (Show Source): You can put this solution on YOUR website!This is all places where y=-4. So go straight down on the vertical (up and down) axis and you will find the value where y=-4, but y=-4 anywhere to the left or right of that point also, so the line y=-4 is all of those values. The slope is 0. Here is an online whiteboard that I use while I am working problems on algebra.com. Although you can access it anytime, I only monitor it while I am working problems. http://www.scribblar.com/whh9htqcx
 Linear-equations/499754: eve's custom cuts has a graph displaying data from a recent day of work. at what rate does eve work?1 solutions Answer 337837 by MRperkins(300)   on 2011-09-18 14:14:36 (Show Source): You can put this solution on YOUR website!That depends on the graph. Here is an online whiteboard that I use while I am working problems on algebra.com. Although you can access it anytime, I only monitor it while I am working problems. http://www.scribblar.com/whh9htqcx
 logarithm/499734: what is the single logarithm of logaX=logaY-logaZ1 solutions Answer 337835 by MRperkins(300)   on 2011-09-18 14:06:45 (Show Source): You can put this solution on YOUR website!logaX=loga(y/z) 0=loga(y/z)-logaX 0=loga(y/(xz)) Here is an online whiteboard that I use while I am working problems on algebra.com. Although you can access it anytime, I only monitor it while I am working problems. http://www.scribblar.com/whh9htqcx
 Polynomials-and-rational-expressions/499478: Identify the degree of each term of the polynomial and the degree of the polynomial. -9x^3+5x^2+5x+5= The degree of the first term is ________ The degree of the second term is __________ The degree of the third term is _________ The degree of the fourth term is __________ The degree of the polynomial is ___________1 solutions Answer 337722 by MRperkins(300)   on 2011-09-17 22:31:29 (Show Source): You can put this solution on YOUR website!3-first term 2-second term 1-third term 0-fourth term 3-polynomial
 test/499479: (6•6)/61 solutions Answer 337721 by MRperkins(300)   on 2011-09-17 22:30:08 (Show Source): You can put this solution on YOUR website!=6
 Length-and-distance/499471: whats the perimeter of l(0,1) m(3,5) n(5,5) p(5,1)? 1 solutions Answer 337720 by MRperkins(300)   on 2011-09-17 22:28:16 (Show Source): You can put this solution on YOUR website!There are different methods of solving this, but the first step is to plot all the points on a graph. Next, you can either use the distance formula, simply count the squares, or use the pythagorean theorem. You can count squares for all but 1 side and I would recommend using the pythagorean theorem to find that side. The side lengths are 5,4,2,5 therefore, the perimeter is the distance around the quadrilateral, which is 5+4+2+5=16. There may be units for this as well, so make sure you include units.
 Quadratic_Equations/499477: For the following equation, state the value of the discriminate and then describe the nature of the solutions. -19x^2+8x+8=0 What is the value of the discriminant? Which one of the statements below is correct? A-The equation has two imaginary solutions. B-The equation has two real solutions. C-The equation has one real solution. 1 solutions Answer 337719 by MRperkins(300)   on 2011-09-17 22:21:36 (Show Source): You can put this solution on YOUR website!The discriminant is what is under the square root sign of the quadratic equation: if the discriminant is positive, then there are 2 real solutions, if it is 0, then there is 1 real solution, and if it is negative, then it has 2 imaginary solutions. Let me know if this helps.
 real-numbers/499473: What are the differences of Real numbers, irrationals, rationals,integers,whole numbers and natural numbers?1 solutions Answer 337718 by MRperkins(300)   on 2011-09-17 22:15:24 (Show Source): You can put this solution on YOUR website!natural numbers are numbers we count with. We don't count with 0, so 0 is not included. (1,2,3,4...) whole numbers add the 0 to the natural numbers, so (0,1,2,3,...) Integers include negative numbers (-2,-1,0,1,2,...) rationals can be written as a fraction of two integers a and b (-a/b, a/b...) irrationals can not be written as a fraction. They are non repeating numbers like the square root of 2 or pi real numbers include all rationals, irrationals and everything. They do not include square root of negative numbers though. Hope this helps.
 Polynomials-and-rational-expressions/499472: Find the value of the expression when z=-7. 2z-1/z-81 solutions Answer 337717 by MRperkins(300)   on 2011-09-17 22:03:21 (Show Source): You can put this solution on YOUR website!substitute -7 for z into the expression. Put parenthesis around it so you don't get confused. I think that you may have your expression written wrong, so I am hesitant to solve this for you. will equal is different than the second equation will be equal to 1, the first equation will be a fraction