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richwmiller answered: 9124 problems
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Polynomials-and-rational-expressions/254997: What is the Factor of 5x+40? 1 solutions Answer 187291 by richwmiller(9135)   on 2010-01-08 20:15:44 (Show Source): You can put this solution on YOUR website! I believe you mean, "What are the factors of 5x+40 ?" The 5 should be hint that we want to factor out 5. You can't factor 5 itself because 5 has no factors. Let's factor out 5. 5*(x+8)

Geometry_proofs/254991: Given: E is the midpoint of BC AB is parallel to CD Prove: AB is congruent to CD 1 solutions Answer 187290 by richwmiller(9135)   on 2010-01-08 20:11:57 (Show Source): You can put this solution on YOUR website! I fixed spelling errors and math conventions. Was there figure? a drawing?

Rational-functions/254984: 4x^3-27x^2-11x-1=0 1 solutions Answer 187288 by richwmiller(9135)   on 2010-01-08 20:04:21 (Show Source): You can put this solution on YOUR website! factor it (4x+1)*(x^2-7x-1) = 0 three solutions 4x+1=0 solve for x x^2-7x-1=0 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 : . Discriminant d=45 is greater than zero. That means that there are two solutions: . Quadratic expression can be factored: Again, the answer is: 6.85410196624968, 0.145898033750315. Here's your graph:

Linear-equations/254982: A roof rises 9.75 ft over a horizontal distance of 17.24 ft. What is the slope of the roof to the nearest hundredth. 1 solutions Answer 187284 by richwmiller(9135)   on 2010-01-08 19:55:19 (Show Source): You can put this solution on YOUR website! slope is rise(vertical) over run (horizontal) slope=9.75/17.24

Linear-equations/254988: If an inventor of a new product charges $4 per unit, then her profit for producing and selling X units given by the function: P(x)= 2.25x-7000. A. What is her profit if she sells 2000 units B. What is her profit if she sells 5000 units C. What is the break even point for sales 1 solutions Answer 187283 by richwmiller(9135)   on 2010-01-08 19:53:12 (Show Source): You can put this solution on YOUR website! A)Plug in P(2000)=2.25(2000)-7000 b)Plug in P(5000)=2.25(5000)-7000 C)2.25x=7000 solve for x x=7000/2.25

Linear-equations/254983: find the slope and y intercept: X= -8 1 solutions Answer 187281 by richwmiller(9135)   on 2010-01-08 19:47:15 (Show Source): You can put this solution on YOUR website! x=-8 This is a special case because y can be anything but x is always -8 There is no y intercept. The y intercept means when x=0. It is a vertical line and even the slope is messed up. Slope is the change in y over the change in x. But x never changes and the change equals 0 Division by zero is undefined. So the slope is undefined. And not only are the y intercept and slope different but this isn't even a function. A function has one y for each x. Here we have an infinite number of y for one x.

Linear-equations/254976: okay i need help on this problem. I've tried different ways to solve it but i can't seem to the find the answer. I NEED help., PLEASE. Find the standard form of the equation of the line that passes through the point (-3, -5) and is parallel to the line 2x-3y=-6. 1 solutions Answer 187275 by richwmiller(9135)   on 2010-01-08 19:35:20 (Show Source): You can put this solution on YOUR website! There is the standard form and the slope intercept form. y=mx+b is the slope intercept form where m is the slope and b is the y intercept when x=0 The standard form is ax+by=c where the slope is -a/b The b's mean different things in each equation. Don't get confused. They are not the same b. Let's look at your equation 2x-3y=-6 It is in standard form The slope is -a/b=-(2/-3)=2/3 We want a line parallel which means with the same slope. (y-y1)=2/3(x-x1) y-(-3)=2/3(x-(-5)) y+3=2/3(x+5) y+3=2/3x+2/3(5) y+3=2x/3+10/3 Subtract 3 from both sides 10/3=3 1/3 y=2x/3+1/3 in slope intercept form Multiply by 3 3y=2x+1 Subtract 2x -2x+3y=1 in standard form

Mixture_Word_Problems/254975: hi Im not sure what kind of problem this is for sure but I think its a mixtuer problem. how do you solve this word problem Cole has a solution that is 20% water and another solution that is 60% water. He wants to mix these to make a 40 mL of each solution that is 30% water. How many mL of each solution should Cole mix together? I copied the question exactia ly how it was in my algebra 1 book. 1 solutions Answer 187267 by richwmiller(9135)   on 2010-01-08 19:11:57 (Show Source): You can put this solution on YOUR website! .20x +.60(40-x)= .30*40 There you go. Now all you have to do is multiply everything out and solve for x and 40-x. Remember that x is the amount of 20% solution and 40-x is the 60% solution. Most people have trouble setting up the equations but can do the math. BTW I lost confidence in your ability to copy when I saw "exactialy." Exactly is the right spelling. Why is spelling important in math? It has to do with paying attention to details. Math especially word problems is about details. Spelling is a detail.

Geometric_formulas/254977: Find the value of the variable that is not given.P=a+b+c (perimeter of a triangle); P=12, a=3,c=5. The answer was b=4 but i was not sure how to get to that answer or how to solve it. 1 solutions Answer 187260 by richwmiller(9135)   on 2010-01-08 18:57:22 (Show Source): You can put this solution on YOUR website! P=a+b+c 12=3+b+5 subtract 3 from both sides then subtract 5 from both sides that is b

Linear_Equations_And_Systems_Word_Problems/254978: an aquarium is 22 inches long 12 inches wide and24 inches high.the volume of the water in it is 1584 cubic inches. what is the height of the water? I cannot set up an equation for this. Help! 1 solutions Answer 187258 by richwmiller(9135)   on 2010-01-08 18:55:22 (Show Source): You can put this solution on YOUR website! volume =L*w*h They are tricking you by telling you the height of the aquarium. We don't care. We want the height of the water. But your answer h shouldn't be over 24 inches the height of the aquarium. 1584=22*12*h (1584)/(22*12)=h Solve for h I hope there are no fish in it because there is very little water.

Quadratic-relations-and-conic-sections/254966: y=x squared-12x+20 simplify into the parabala equasion 1 solutions Answer 187254 by richwmiller(9135)   on 2010-01-08 18:36:22 (Show Source): You can put this solution on YOUR website! You need to learn the language of math. squared is ^2 ^ is over the 6 and spelling parabola not parabala and equation not equasion y=x^2-12x+20 It already is a parabola equation. Maybe you mean factor Solved by pluggable solver: Factoring using the AC method (Factor by Grouping) In order to factor , first multiply the leading coefficient 1 and the last term 20 to get 20. Now we need to ask ourselves: What two numbers multiply to 20 and add to -12? Lets find out by listing all of the possible factors of 20 Factors: 1,2,4,5,10,20, -1,-2,-4,-5,-10,-20, List the negative factors as well. This will allow us to find all possible combinations These factors pair up to multiply to 20. 1*20=20 2*10=20 4*5=20 (-1)*(-20)=20 (-2)*(-10)=20 (-4)*(-5)=20 note: remember two negative numbers multiplied together make a positive number Now which of these pairs add to -12? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to -12 |||||| First Number | Second Number | Sum 1 | 20 | 1+20=21 2 | 10 | 2+10=12 4 | 5 | 4+5=9 -1 | -20 | -1+(-20)=-21 -2 | -10 | -2+(-10)=-12 -4 | -5 | -4+(-5)=-9 We can see from the table that -2 and -10 add to -12. So the two numbers that multiply to 20 and add to -12 are: -2 and -10 So the original quadratic breaks down to this (just replace with the two numbers that multiply to 20 and add to -12, which are: -2 and -10) Replace with Group the first two terms together and the last two terms together like this: Factor a 1x out of the first group and factor a -10 out of the second group. Now since we have a common term we can combine the two terms. Combine like terms. ============================================================================== Answer: So the quadratic factors to Notice how foils back to our original problem . This verifies our answer.

Linear-equations/254973: y^2=x Which I figure to be y=sqrt(x)... When I graph it on my TI-89, it does not create a continuous line but stops 0. My answer key shows it continuing through the negative spectrum of y. Is the answer key wrong, or am I wrong in making the equations y=sqrt(x). Sorry for the pathetically dumb questions. I haven't done algebra in over a decade, and the book I bought is very sparse on explanation. It's more of a workbook than anything. 1 solutions Answer 187251 by richwmiller(9135)   on 2010-01-08 18:29:35 (Show Source): You can put this solution on YOUR website! You left out other half. It should be plus or minus sqrt(x) y=+\-sqrt(x) It is better to leave it as y^2=x for graphing Don't feel bad after 10 years. I am refreshing my memory after 45 years of not doing math

Polynomials-and-rational-expressions/254964: Factor out the greatest common factor. 16y^5 - 24y^4 - 40y^3 1 solutions Answer 187248 by richwmiller(9135)   on 2010-01-08 18:23:46 (Show Source): You can put this solution on YOUR website! 16y^5 - 24y^4 - 40y^3 start with 4y^3 4y^3(4y^2-6y-10) We could have gone higher than 4 let's go 2 4y^3*2(2y^2-3y-5) 8y^3(2y^2-3y-5) Now we get to the fun part we want factors of 2*-5 that add to -3 and we have them 2y^2 +2y -5y-5 group them 2y(y+1) -5(y+1) (2y-5)(y+1) 8y^3*(y+1)*(2y-5)

Polygons/247763: P=2L+2W and A=LW A)if the length of the rectangle is doubled what is the effect on the perimeter of the rectangle? on the area of the rectangle? what happens to the perimeter and to the area if both the length and the width are doubled? B) if the length of the rectangle is tripled what is the effect on the perimeter of the rectangle? on the area of the rectangle? what happens to the perimeter and to the area if both the length and the width are tripled? C)if the rectangle is increased by a factor of n what is the effect on the perimeter of the rectangle? on the area of the rectangle? what happens to the perimeter and to the area if both the length and the width are increased by a factor of n? 1 solutions Answer 187244 by richwmiller(9135)   on 2010-01-08 18:03:44 (Show Source): You can put this solution on YOUR website! Just plug in 2 and 1 and for the measurements L and w and then 4 and 2 and see the difference in area and perimeter

Equations/254927: Consecutive odd integers. Find two consecutive odd intergers whose sum is 56. 1 solutions Answer 187215 by richwmiller(9135)   on 2010-01-08 15:13:32 (Show Source): You can put this solution on YOUR website! n+n+2=56 2n=54 n=27 n+2=29

Triangles/254928: in this triangle, side AC=12, side BC=16, and side AB=20, is triangle ABC a right triangle? 1 solutions Answer 187214 by richwmiller(9135)   on 2010-01-08 15:11:27 (Show Source): You can put this solution on YOUR website! divide each side by 4 12/4 =3 16/4 =4 20/4 =5 This is a classic special 3,4 ,5 right triangle

Circles/253981: Sammy has a circular pool in his backyard. The diameter of the pool is 15 feet. What is the circumference of the pool? 1 solutions Answer 187206 by richwmiller(9135)   on 2010-01-08 14:30:20 (Show Source): You can put this solution on YOUR website! d=2r d=15 c=2*pi*r c=15*pi

Equations/254909: F(x)= x^3-5x^2+144x-720 I got one of the zeroes (x=5) I need the other 2... they should be imaginary numbers. 1 solutions Answer 187204 by richwmiller(9135)   on 2010-01-08 14:27:24 (Show Source): You can put this solution on YOUR website! y = (x-5) (x^2+144) you should able to figure this out x^2+144=0 x^2=-144 and you are right there is an i in there.

Linear_Algebra/254912: solve with a calculator y^2-4x^2=16 2x^2+y^2=16 i dont know how to do this in the calculator 1 solutions Answer 187201 by richwmiller(9135)   on 2010-01-08 14:24:09 (Show Source): You can put this solution on YOUR website! not all calculators can do it.

Radicals/254892: for positive real numbers x,y,z, what is the equivalent to x^1/2 y^2/3 z^5/6? a. 3 sqrt xy^2 z^3 b. 6 sqrt xy^2 z^5 c. 6 sqrt x^3 y^2 z^5 d. 6 sqrt x^3 y^4 z^5 e. 11 sqrt xy^2 z^5 i guessed d. b/c i multiplied 6*3 =18, then i put 18/6 = 1/2 ...but i need help please am i doing this all wrong? 1 solutions Answer 187185 by richwmiller(9135)   on 2010-01-08 12:41:06 (Show Source): You can put this solution on YOUR website! You are cute.

Points-lines-and-rays/254888: We have four math problems. They are: 1) Draw a sketch of a quares with a perimeter of 80 units. 1 solutions Answer 187184 by richwmiller(9135)   on 2010-01-08 12:25:24 (Show Source): You can put this solution on YOUR website! The website rules say: One problem per submission No more than 4 submissions daily No similar problems What are quares? Anything like squares?

Human-and-algebraic-language/254891: When a number is decreased by 30% the result is 140, what number is it? 1 solutions Answer 187182 by richwmiller(9135)   on 2010-01-08 12:22:55 (Show Source): You can put this solution on YOUR website! If a number is decreased by 30% we end up with 70% of that number 70%=.70==.7=7/10 7x/10=140 7x=1400 x=1400/7 x=200 check 70% of 200=140 0k

Equations/254884: Need answer for these problems please. Simplify by remaining factors of 1: 5w-45/5w and v to the second power - 36/6-v. 1 solutions Answer 187181 by richwmiller(9135)   on 2010-01-08 12:19:58 (Show Source): You can put this solution on YOUR website! one problem per submission no similar problems limit of 4 submissions daily Please the right way to enter sqaures 2^2 is 2 squared 2^3 is 2 cubed etc ^ above the 6 on your keyboard

logarithm/254879: What is the solution set for: 5y-4=11y+26 1 solutions Answer 187176 by richwmiller(9135)   on 2010-01-08 11:40:47 (Show Source): You can put this solution on YOUR website! This has nothing to do with logarithms 5y-4=11y+26 add 4 5y=11y+30 -6y=30 y=-5 check 5*-5-4=11*-5+26 -25-4=-55+26 -29=-29 ok

Linear_Equations_And_Systems_Word_Problems/254863: you are in charge of constructing a fence around the running track at a high school. the fence is to be built around the track so that there is a uniform gap between the outside edge of the track and the fence. a. what is the maximum width of the gap between the track and the fence if no more than 630 meters of fencing is used? (hint: use the equation for the circumference of a circle.) 1 solutions Answer 187175 by richwmiller(9135)   on 2010-01-08 11:36:25 (Show Source): You can put this solution on YOUR website! This not a linear equation since it involves a circle. We can't calculate a gap because we don't know the size of the track. We can calculate a fence of 630 meters. 630 =pi*r^2 could have up to a radius of 14.161

Geometry_proofs/254878: I cant understand proofs as hard as I try.I either put the wrong reasons and statements or cant find any statments or reasons to put.I really want to know how I can better understand proofs.My teacher is no help.So please HELP!! :( 1 solutions Answer 187174 by richwmiller(9135)   on 2010-01-08 11:27:15 (Show Source): You can put this solution on YOUR website! We start with what we know and proceed to what we want to know. Other than that we need examples of where you have gone wrong. Sounds like something just isn't clicking. So send some examples of what you have done wrong. and maybe some of what you have done right.

Linear_Equations_And_Systems_Word_Problems/248927: Here's my problem: Two friends live 15 miles apart. One day, they decided to jog and meet each other. Tanya leaves her house and heads east, jogging at a rate of 2.5 miles per hour. At the same time Kelly leaves her house and heads west, jogging at a rate of 3.5 miles per hour. How long does it take for the two to meet? Thank you. 1 solutions Answer 187172 by richwmiller(9135)   on 2010-01-08 11:18:21 (Show Source): You can put this solution on YOUR website! rt=d rt+rt=d times will be the same 2.5t+3.5t=15 t(6)=15 t=15/6=5/3=1 2/3 =1 hr 40 minutes

Linear-systems/254864: how would I write an equation for the following linear relationships: (x5,y20),(x10,y30)(x15,y40)(x20,y50)(x25,y50)(x30,y50) 1 solutions Answer 187171 by richwmiller(9135)   on 2010-01-08 11:12:41 (Show Source): You can put this solution on YOUR website! There is something wrong because y doesn't change in the last three. that can't be a linear equation since y does change in the first three. I think the last three y's should be 50 60 70. 10/5=slope (y-y1)=m(x-x1) (y-20)=m(x-5) y-20=2x-10 y=2x+10

Travel_Word_Problems/254872: 6[8-2(3-9)]= 1 solutions Answer 187169 by richwmiller(9135)   on 2010-01-08 10:58:16 (Show Source): You can put this solution on YOUR website! start as far in as possible and do the addition or subtraction So you would do 3-9 first -6 then you have -2(-6)=+12 then you have 8+12=20 then you have 6*20=120

Linear-systems/254867: Hi! I need help with this equation. The directions read determine if each equation is a direct variation. If it is, find the constant of variation. The first equation is 2y=5x+1 -Thanks -Drea 1 solutions Answer 187168 by richwmiller(9135)   on 2010-01-08 10:44:48 (Show Source): You can put this solution on YOUR website! 2y=5x+1 y=2.5x+1/2 They probably do not consider this direct variation because of the 1/2

Expressions-with-variables/254861: how do you solve... 2x+o.87+2x+1.69+2x+1.99+1x+1.89 ? 1 solutions Answer 187166 by richwmiller(9135)   on 2010-01-08 10:35:36 (Show Source): You can put this solution on YOUR website! There is no real "solve it" There is no equal sign. We can reduce it we can simplify it we can factor it So to simplify add up all the x's and all the numbers That all boils down to 7x+6.44