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vleith answered: 2822 problems
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 Polynomials-and-rational-expressions/210366: Hi I have three problem that I have to perform operation on and show my work. -5x(3x^2-4x-9) (5-3x)(4+7x) (3x+5)^21 solutions Answer 158978 by vleith(2825)   on 2009-09-02 11:13:36 (Show Source):
 Quadratic_Equations/210380: Use the quadratic formula to determine the x intercepts (if any) of the following function. Then evaluate the function for several values of x, and use the resulting points to graph the function. Show your work. f(x)=7x^2-2 I have already come up with what I believe is the solution of the quadrtic, x=0.534 x= -0.534.I don't understand how to get the other points on the graph and have it look like it's supposed to. Thanks 1 solutions Answer 158977 by vleith(2825)   on 2009-09-02 11:10:02 (Show Source): You can put this solution on YOUR website!You have the correct x intercepts. Now you need to find the minimum point. You can see by looking at the function that the value will cause f(x) to be as small as it can get. So calculate f(0) = Plot the points (0, -2), (0.534, 0) and (-0.534, 0) Now draw a nice parabola thru them. If you need more points, just pick some x values (like 1 and -1), evaluate f(x) at those values for x and then plot those points too
 Coordinate-system/210385: without graphing, fing the minimum value f(x)=3(x+12.68)^2-sqrt221 solutions Answer 158974 by vleith(2825)   on 2009-09-02 11:01:05 (Show Source): You can put this solution on YOUR website!Without graphing, to find the minimum value, you need to look at the terms and see which one(s) can change. You know that is a constant, so that one won't change. You can see that the first term involves a factor of that includes a square. You know that the minimum a squared value can be is 0 (A squared value is always going to be positive or 0). So the minimum value occurs when the first term is 0. So what value of x makes When x = -12.68, then
 Percentage-and-ratio-word-problems/210362: what if at party, Leda Marie cut each buko pie into 2 serving pieces.If 63 halves pieces were eaten,how many pies were serve?1 solutions Answer 158968 by vleith(2825)   on 2009-09-02 10:26:55 (Show Source): You can put this solution on YOUR website!Hard to say how many were served - we can say the minimum needed to make 63 peices. We know that 63 halves were eaten, so 63/2 = 31.5 full pies. She must have served at least 32 pies
 Rectangles/210368: Find the maximum area of 45 the given perimeter of a rectangle. State the length and width of the rectangle.1 solutions Answer 158966 by vleith(2825)   on 2009-09-02 10:23:47 (Show Source): You can put this solution on YOUR website!rule of thumb: the maximum area for a given rectangle perimeter is always a square. So in that case both the length and width are the same. Call it x
 percentage/210375: Compute the requested value. Choose the correct answer. If the selling price is \$75.50 and includes the cost plus 5% of the cost, then what is the cost?1 solutions Answer 158963 by vleith(2825)   on 2009-09-02 10:21:33 (Show Source):
 Graphs/210378: Hi, I'm having a little difficulty completing my project for algebra. Here's my question........ In a plotted graph, the x-axis represent weight and the y-axis represent miles. What would a slope of -13/22 mean? Is it for every 13 miles decreasing the weight decreases by 22 pounds??????1 solutions Answer 158962 by vleith(2825)   on 2009-09-02 10:20:04 (Show Source): You can put this solution on YOUR website!Close ... but not quite For each decrease of 13 miles (-13), the weight increases by 22 (22)
 Linear_Algebra/210370: L=G m1m2/t^2 solve for m11 solutions Answer 158961 by vleith(2825)   on 2009-09-02 10:16:28 (Show Source): You can put this solution on YOUR website! mutliply both sides by divide both sides by
 Linear_Algebra/210374: 2x+y=8 solve for y1 solutions Answer 158960 by vleith(2825)   on 2009-09-02 10:13:52 (Show Source): You can put this solution on YOUR website! solve for y by subtracting 2x from each side. This isolates y by itself on the left hand side
 Probability-and-statistics/210376: i can not figure this one out. can someone just tell me how to calculate.7 of 20,000. i get 14000 and that would only leave 6,000 which isnt an option. help please!!! A contractor is considering a sale that promises a profit of \$ 20,000 with a probability of .7 or a loss (due to bad weather, strikes, and such) of \$ 3000 with a probability of .3. What is the expected profit? A) \$ 16,100 B) \$ 17,000 C) \$ 13,100 D) \$ 14,000 1 solutions Answer 158959 by vleith(2825)   on 2009-09-02 10:12:15 (Show Source): You can put this solution on YOUR website!I think the question here is what does the contractor expect when a large enough set of similar deals happens. You are told that contractor expects to make 20,000 70% of the time and lose 3000 30% of the time. So what can the contractor expect if he/she does a bunch of these deals?
 Numbers_Word_Problems/210342: in how many ways can 72 be expressed as product of two-digit Even numbers1 solutions Answer 158947 by vleith(2825)   on 2009-09-02 06:21:27 (Show Source): You can put this solution on YOUR website!This is a really bad question. I assume what they are really asking is "How many ways can 72 be expressed as a product of two-digit even Integers". That answer would be: None. For a quick check, use the smallest 2 digit even number --> 10 If 10 is used, the 'other number' would be 7.2. Any even number larger than 10 would make the other number smaller than 7.2. Since 7.2 is NOT a two digit integer, then the answer is "none". So what makes this a bad question? The fact that the problem asked for two digit even 'numbers'. Since 10 and 7.2 both contain two digits, and are both even, then they work. Since there is going to be a "really big' number of similar two-digit (albeit non-integral) numbers, makes the answer to this one a mess.
 Exponents/210343: 2/3 of a nunber decreased by 7=27.what is the number1 solutions Answer 158946 by vleith(2825)   on 2009-09-02 06:14:37 (Show Source): You can put this solution on YOUR website!Let the number be represented by x. Using the info in the problem:
 expressions/209966: can anyone solve this 3a+5(4a+6)=361 solutions Answer 158672 by vleith(2825)   on 2009-08-31 20:06:42 (Show Source):
 Probability-and-statistics/209965: A bag contains 37 marbles. There are 10 red, 4 green, 9 yellow and the rest are blue. You reach into the bag, take out a marble, it is red. you set this marble in a bowl on the table and reach in the bag again. What is the probability that you will reach in and pull out a blue marble?1 solutions Answer 158670 by vleith(2825)   on 2009-08-31 20:05:13 (Show Source): You can put this solution on YOUR website!first figure out how many blue marbles there are After you draw one red marble, there are 36 marbles left in the bag. So the probability of picking a blue marble = = =
 Graphs/209958: This question is from textbook Moving straight ahead Linear RelationShips Im totaly lost on my 8th grade math homework. It says *For each equations in Exercises 18-21, give two values for x for which the value of y is negative.* For 18. y=-2x-5 19. y= -4 20. y=2x-5 21. y=3/2x-1/41 solutions Answer 158668 by vleith(2825)   on 2009-08-31 20:01:35 (Show Source): You can put this solution on YOUR website!18) for y to be negative here, any x that is positive will do. Even x=0 would make y negative You could solve it algebraically this way. In order for y to be negative, it must be "less than 0" so any x that is larger than -2.5 will give you a y that is negative. Look at the plot and you can see the same thing 19) y= -4 This is a horizontal line. So all x, no matter what value has a y = -4 20) In this much like 18. Any x less than 2.5 yields a y that is negative 21) Same idea here Any x less than 1/6 works
 expressions/209959: CAN ANYONE SOLVE THIS 3a+5(4a+6)1 solutions Answer 158663 by vleith(2825)   on 2009-08-31 19:49:45 (Show Source):
 Graphs/209800: Why does the equation y=(0.5)^x not have an x- intercept, using algebra?1 solutions Answer 158586 by vleith(2825)   on 2009-08-31 06:15:31 (Show Source): You can put this solution on YOUR website!In order for a point to be an 'x-intercept', the y coordinate must be 0. Let's substitute in y=0 and then attempt to solve for x The Log(0) is undefined, so y cannot be 0. You can also try it another way As x increases, the value of approaches 0. However, 0 is the asymptote --> y never 'quite gets to 0, just really really close'
 Miscellaneous_Word_Problems/207887: A rectangular deck has an area of (x2 + 6x + 8) square feet. If its width is (x + 2) feet then: a. Find its length in terms of ‘x’. b. If x = 3, what will be the area, length and width in feet. 1 solutions Answer 157242 by vleith(2825)   on 2009-08-22 07:44:21 (Show Source): You can put this solution on YOUR website!Area = (x^2 + 6x + 8) Width = (x +2) Area = Length * Width Area/Width = Length If x=3 what are the area, length and width Width = (x+2) = 3+2 = 5 Length = (x+4) = (3+4) = 7 Area = x^2 +6x + 8 = 3^2 + 6*3 + 8 = 9 + 18 + 8 = 35 Area = Length*Widht = 7 * 5 = 35
 Miscellaneous_Word_Problems/207888: If a ball is thrown upwards at 40 feet per second from a rooftop 24 feet above the ground, then its height above the ground t seconds after it is thrown is given by h = - 16 t2 + 40 t + 24. a. Rewrite the above formula with the polynomial on the right hand side factored completely. b. Use the factored version of the formula to find h when t = 3. 1 solutions Answer 157241 by vleith(2825)   on 2009-08-22 07:40:26 (Show Source): You can put this solution on YOUR website! You can see that at t=3, the term (t-3) above would evaluate to 0. Since 0* anything = 0, then h(3) = 0.
 Graphs/207794: i posted these problems 4 days ago,but haven't received a response.could someone please help me.Thanks. sketch the graphs,using the roots to find the function and the turning point 1.x = -8, x = 4 2.x = -3, x = 3 thanks for the help.hagd 1 solutions Answer 157180 by vleith(2825)   on 2009-08-21 15:19:23 (Show Source): You can put this solution on YOUR website!You are given roots, so you can figure out the quadratic. I will do the first one, you can use the same process to do the second one 1) roots are x=-8 and x=4 You know that at the roots, the value of the function is 0 You also know that for any product to equal zero, one or more terms in that function must be 0. Thus x =-8 x+8 = 0 x= 4 x-4=0 Now you have the two terms for your equation This is the equation for the first problem. Since is it q quadratic, you know it is a parabola that opens up (opens up since the x^2 term is positive). You also know that the 'turning point' will be halfway between the two root. Since the roots are 12 units apart, the 'turning point' will be 6 units from each root. -8+6 = -2 4-6 = -2 So find the value of f(x) when x=-2 and you'll have the minimum. So the 'turning point is the point (2,-20) Plot the funtion here --> http://www.wolframalpha.com/input/?i=x^2+%2B+4x+-+32+ Now do the same process for the other one. I am sure you can do it. If you still have questions, drop me an email
 Graphs/207795: please help. I am trying to teach this to my daughter,but I need step by step instructions in order to do so .Thanks solve for the unknown 1.5 = sqrt a + 2 (the 2 is not inside the sqrt symbol) 2.33 + 4 sqrt a = 6 sqrt a - 7 (7 is not inside the sqrt symbol) thanks for the help. I really appreciate it.1 solutions Answer 157179 by vleith(2825)   on 2009-08-21 15:09:08 (Show Source): You can put this solution on YOUR website!1) 2) check your answers
 test/207798: Please help me with this problem: Write and solve an equation to find the value of x. 4.8, 1.6, 5.2, x; mean 3.7 Thanks!1 solutions Answer 157177 by vleith(2825)   on 2009-08-21 15:03:13 (Show Source): You can put this solution on YOUR website!The mean is the average. There are 4 values to include in the calculation Check your answer.
 Polynomials-and-rational-expressions/207789: This question is from textbook Introductory Algebra Please help me Preform the indicated operations and simplify: -*1 solutions Answer 157174 by vleith(2825)   on 2009-08-21 14:42:35 (Show Source):
 Miscellaneous_Word_Problems/207756: Turner agrees to buy a boat for \$2,800 down and \$129 a month for 48 months. What is the total cost of the boat?1 solutions Answer 157143 by vleith(2825)   on 2009-08-21 09:00:16 (Show Source):
 Miscellaneous_Word_Problems/207757: A stack of 1/2 plywood is 35 in. high. How many sheets of plywood are in the stack?1 solutions Answer 157142 by vleith(2825)   on 2009-08-21 08:57:16 (Show Source): You can put this solution on YOUR website!Each sheet is 1/2 inch thick
 Problems-with-consecutive-odd-even-integers/207762: This question is from textbook algebra 1 an integrated approach x/4+10>2 solve the problem 1 solutions Answer 157141 by vleith(2825)   on 2009-08-21 08:55:32 (Show Source): You can put this solution on YOUR website! plot is here --> http://www.wolframalpha.com/input/?i=x%2F4%2B10%3E2
 absolute-value/207763: |n-(-4)|=6 n=___or___1 solutions Answer 157139 by vleith(2825)   on 2009-08-21 08:53:54 (Show Source): You can put this solution on YOUR website! So that means or or or
 Volume/207749: Silver metal has a density of 10.5g/cm^3. A solid sphere of silver has mass of 0.295 g. What is the diameter of the silver piece, in mm? The volume of a sphere is V= (4/3)3.14*r^3 . I do not even know where to start with this.1 solutions Answer 157133 by vleith(2825)   on 2009-08-21 04:52:20 (Show Source): You can put this solution on YOUR website!You are given the density of silver and told about a silver sphere that has a mass of 0.295g. So you need to find the diameter of a sphere that with that mass. First let's figure out what volume the sphere must be. You are asked to find the sphere's diamter in mm. So let's convert the volume to (mm)^3 There are 10 mm/cm, so the converion from (mm)^3/(cm)^3 = 10*10*10 = 1000(mm)^3/(cm)^3 You are ready ro solve Now just grind out the value for r. Once you have that, you need to remember you were asked for the diameter. So just double the radius and you are there.
 Miscellaneous_Word_Problems/207607: A toy manufacturer produces model cars which are similar in every way to the actual cars. If the ratio of the door area of the model to the door area of the car is 1:2500, find the ratio of the capacites of their petrol tanks1 solutions Answer 156995 by vleith(2825)   on 2009-08-20 10:04:44 (Show Source): You can put this solution on YOUR website!First find the linear scale. You are told two areas are scaled at 1:2500 You know area is measured in squared linear dimension. SO, what is the sqaureroot of 2500? Thus the linear scale is 1:50 Now, you are asked about 'capacity of the petrol tanks'. That is a volume. And volume are in cubic dimensions. So the scale needs to be cubed wow
 Coordinate-system/207611: 3x + 4y =12 graph the equation on the coordinate system1 solutions Answer 156993 by vleith(2825)   on 2009-08-20 10:00:30 (Show Source): You can put this solution on YOUR website!The given equation is a line. So you need to find two points and then plot them. For me, the easiest points to calculate are ones that have a 0 in one of the coordinates. So let's find the point with where x=0 So one point is (0,3) Now find the point with a y coordinate of 0 Another point is (4,0) Now, plot those two points (0,3) and (4,0). Then draw the line that contains those two points. See this URL for a plot --> http://www.wolframalpha.com/input/?i=3x+%2B+4y+%3D12