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Recent problems solved by 'scott8148'
scott8148 answered: 6619 problems
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Linear-equations/580657: How do I graph equations by using slope and y intercept?
Ex. y=3x+2
1 solutions
Answer 371330 by scott8148(6628)   on 2012-03-01 10:47:52 (Show Source):
You can put this solution on YOUR website!the y-intercept gives you a starting point ___ this is the place where the line of the graph crosses the y-axis
in the example, the intercept is 2 ___ so go to 2, ON the y-axis, and mark a point
the slope of the graph is indicated by the x-coefficient in the equation
___ it is the RATIO of the CHANGE in the y-value, to the CHANGE in the x-value
in the example, the slope is 3 ___ this means that for every three units that y increases, x increases by one unit
starting at the y-intercept (0,2), go up 3 units and to the right one unit, to (1,5)
___ do the same thing again to go to (2,8)
___ these are points of the linear graph
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Travel_Word_Problems/580262: The average speed of an express train is 14 miles per hour more than 1/3 the speed of a freight train. In two hours the express train travels the same distance as the freight rain in three hours. Find the average speed of each train. I need the answer before tomorrow! Please Help Me.
1 solutions
Answer 371197 by scott8148(6628) on 2012-02-29 18:27:19 (Show Source):
You can put this solution on YOUR website!"The average speed of an express train is 14 miles per hour more than 1/3 the speed of a freight train"
___ e = (f / 3) + 14 ___ 2e = (2f / 3) + 28
"In two hours the express train travels the same distance as the freight rain in three hours
___ 2e = 3f
substituting ___ 3f = (2f / 3) + 28 ___ 9f = 2f + 84 ___ 7f = 84
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Rational-functions/580191: How would you solve... ((1/x)^2-(x)^2)/((1/x)+(x))=(3/2)
When i tried solving it i got stuck when trying to factor it. do not know what to do when there is an (x^40) Please help! thank you :)
1 solutions
Answer 371193 by scott8148(6628) on 2012-02-29 17:31:42 (Show Source):
You can put this solution on YOUR website!if m is 1/x, you then have (m^2 - x^2) / (m + x) = 3/2
factoring ___ [(m + x)(m - x)] / (m + x) = 3/2 ___ m - x = 3/2
replacing m ___ (2/x) - 2x = 3
multiplying by x ___ 2 - 2x^2 = 3x ___ 0 = 2x^2 + 3x - 2
factoring ___ 0 = (2x - 1)(x + 2)
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Average/580166: claudia has an average of 87 in five examination.What grade must she receive on her next test if she wants to raise her average to 89?
1 solutions
Answer 371186 by scott8148(6628) on 2012-02-29 17:15:51 (Show Source):
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Proportions/580099: A group of 10 men can do a job in 50 days. They start the work together, but after x days, 2 men leave the work. The remaining people finish the remaining job in 25 days. What is the value of x ?
Thanks.
1 solutions
Answer 371185 by scott8148(6628) on 2012-02-29 17:13:48 (Show Source):
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Proportions/580107: If the ratio of A:B is 2:5 and the ratio of B:C is 3:4, then what is the ratio A:C?
Please explain how to solve these type of questions.
Thanks.
1 solutions
Answer 371142 by scott8148(6628) on 2012-02-29 15:15:46 (Show Source):
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Permutations/579592: My sister and I are having problems with the process of elimination.
We have to solve the story problem given:
The football team has 45 members. There are twice as many juniors as seniors. How many of each are on the team?
1 solutions
Answer 371027 by scott8148(6628) on 2012-02-28 17:29:06 (Show Source):
You can put this solution on YOUR website!"The football team has 45 members" ___ j + s = 45
"There are twice as many juniors as seniors" ___ j = 2s
subtracting the 2nd equation from the 1st (to eliminate j) ___ j + s - j = 45 - 2s
s = 45 - 2s ___ 3s = 45
solve for s, then substitute back to find j
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Linear-equations/579562: I need help with a problem. Write an equation of the line containing the given point and parallel to the given line. (4,9); x + 2y=9
1 solutions
Answer 371025 by scott8148(6628) on 2012-02-28 17:02:48 (Show Source):
You can put this solution on YOUR website!parallel means that the equation is the same, except for the constant term (9)
to find the new constant term, plug in the given point ___ (4) + 2(9) = ? ___ 22 = ?
the new equation is ___ x + 2y = 22
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Surface-area/579403: Hi. i would like to know if anyone can help me with a problem. i dont understand what to do. I a m stuck. This is the last problem i have to do and i really need some help(: thank you in advance.
The volume of an oblique square pyramid with equal base edge and height is 243cm^3. Find the area of the square base.
If someone could please help me i would highly appreciate it! thankyou for taking the time to read this(:
1 solutions
Answer 370974 by scott8148(6628) on 2012-02-28 11:17:56 (Show Source):
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Polynomials-and-rational-expressions/579391: I am trying to factor this problem. 18x^3-2x
I know I must use a formula. a^3-b^3=(a-b)(a^2+ab+b^2)
This is what I did.
18^3-2x
(18-2)(18^2+9+2^2)
(9-2)(9^2+9+1*2)
2(3+3+1)
This is not the answer and I don't know what I am doing wrong. Can you help me please?
1 solutions
Answer 370969 by scott8148(6628) on 2012-02-28 11:09:54 (Show Source):
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Numeric_Fractions/579053: Can you please help me on this. I am trying to help my son & its been so long since Ive done this stuff. I think I may be right just need confirmation.
3/3 + 4/9=
1 solutions
Answer 370837 by scott8148(6628) on 2012-02-27 18:55:19 (Show Source):
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Linear-equations/579050: LINEAR SYSTEMS ALGEBRA; 7X-3Y=-23, X+5Y=32; AM TRYING TO HELP MY GRANDSON AND HAVE NO IDEA WHERE TO START.
THINK I HAVE DONE ONE CORRECTLY X-Y=3, 2X-2Y=6 (I BELIEVE X = 4 AND Y = 1 BUT DO NOT HAVE ANY IDEA HOW TO SHOW THE WORK;
PLEASE AND THANK YOU
1 solutions
Answer 370836 by scott8148(6628) on 2012-02-27 18:48:06 (Show Source):
You can put this solution on YOUR website!the one you have done "correctly" works for any values of x and y, as long as x is 3 greater than y
___ there is no unique solution
___ this is the case when you can multiply one equation by a constant and get the other equation
x + 5y = 32 ___ x = 32 - 5y ___ substitute this equivalent value for x into the other equation
7(32 - 5y) - 3y = -23 ___ 224 - 35y - 3y = -23 ___ 247 = 38y ___ 247 / 38 = y ___ 13 / 2 = y
x + 5(13 / 2) = 32 ___ x + (65 / 2) = 64 / 2 ___ x = -1 / 2
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Rectangles/578999: The length of a rectangle sign is 4 feet shorter than twice the width. The area of the rectangle is 48 squared feet. Could you help me find the dimensions of the sign?
I tried setting it up as
l(w)= 48sq.ft
2w-4=l
But it's not quite working.
Help please and thanks :)
1 solutions
Answer 370835 by scott8148(6628) on 2012-02-27 18:34:45 (Show Source):
You can put this solution on YOUR website!your equations are okay
substituting ___ (2w - 4)w = 48
dividing by 2 ___ (w - 2)w = 24 ___ w^2 - 2w - 24 = 0
factoring ___ (w - 6)(w + 4) = 0
w + 4 = 0 ___ w = -4 ___ negative value not realistic
w - 6 = 0 ___ w = 6
l = 2(6) - 4 ___ l = 8
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Rational-functions/579036: Help! Please help with this.My teacher did not explain how to go about this.
"write an equation to describe the exponential function as y =ab^x. The base is
4. The graph passes through the point (3,5)"
Thank you so much for the help!
1 solutions
Answer 370832 by scott8148(6628) on 2012-02-27 18:24:40 (Show Source):
You can put this solution on YOUR website!you are given b (the base) and the point (3,5) or (x,y)
plug in the values to find a ___ 5 = a * 4^3 ___ 5 = a * 64 ___ 5/64 = a
y = (5/64) 4^x
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Money_Word_Problems/578888: Lea has 134 and drew has 180 After both of them spent an equal amount of money shopping Drew had 3 times as much as Lea How much did each of them spend?
1 solutions
Answer 370810 by scott8148(6628) on 2012-02-27 14:54:44 (Show Source):
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Sequences-and-series/578862: Here is the sequence : 1/3 ; 1 ; 1/9 ; 4 ; 1/27 ; 7 ; 1/81;...
H e l p m e f i n d t h e n e x t t h r e e t e r m s i n t h e s e q u e n c e .
1 solutions
Answer 370809 by scott8148(6628) on 2012-02-27 14:50:26 (Show Source):
You can put this solution on YOUR website!this looks like an arithmetic series (1, 4, 7) interleaved with a geometric series (1/3, 1/9, 1/27, 1/81)
so the next three terms should be ___ 10, 1/243, 13
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Equations/578788: Word problems are really giving me difficulty. Does anyone have a simple easy rule?
d=rt
Kicking my behind.
A jogger runs at a rate of 10mph. He returns, same route at 6mph. Total trip took 1 hour 36 minutes. How far did he run?
Delena
thanks all!
1 solutions
Answer 370797 by scott8148(6628) on 2012-02-27 13:27:04 (Show Source):
You can put this solution on YOUR website!they give you the total time and the rates
as you say, d = rt ___ but also, t = d / r
(d / 10) + (d / 6) = 1.6
___ the rates are in mi per HOUR, so the time needs to be hours; not hours and minutes
___ 36 min = (36 / 60) hr = (6 / 10) hr = .6 hr
multiplying by 30 (LCD) ___ 3d + 5d = 48 ___ 8d = 48
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Triangles/578794: A first triangle has vertex points at (0,0), (3,4) and (9,12). A second triangle has two vertex points at (2,2) and (-4, 6) and sides of length 10, 20 and 30. These two triangles are..
A Neither Similar nor congruent
B similar and congruent
C not similar but congruent
D similar but congruent
The answer is D. My question is how do you draw the first triangle? When I plot the vertices, it makes a straight line, more or less. So I tried figuring out the side lengths of the first triangle, but can't figure that out either. Please advise on how to construct these triangles and find the side lengths of the first triangle. Thank you!
1 solutions
Answer 370793 by scott8148(6628) on 2012-02-27 13:12:04 (Show Source):
You can put this solution on YOUR website!the 1st "triangle" IS a straight line, but (looking at the side lengths) so is the 2nd
you can use the distance formula to find the side lengths of the 1st triangle
use a compass to construct the 2nd triangle
___ the given vertices are 10 units apart
___ draw an arc of 30 units length from one vertex, and an arc of 20 units length from the other vertex
___ the intersection of the arcs (really a tangency) will show the position of the 3rd vertex
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Percentage-and-ratio-word-problems/578815: A salary increased by 7% is now $625 per week. What was the salary before the raise?
I keep trying the formulas with Base Rate & Portion and keep coming up with 581.25.
$625 X .07 =43.75
625- 43.75 = 581.25
or
$625 X .93=581.25
Why is this not correct?
Thank You
1 solutions
Answer 370789 by scott8148(6628) on 2012-02-27 12:42:07 (Show Source):
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Probability-and-statistics/578753: Here is a question I can't figure out how to get started. I considered using the binomial formula but it looks like it would take ages to calculate, I must be missing the point!
Past car sales experience has shown that 22% of all luxury cars sold are black. If 45 recent sales of luxury cars are randomly selected. Find the following probabilities:
1. At least 2 cars are black.
2. Exactly 6 are black. (I attempted this one using the binomial prob. formula and got 8.9417
3. Between 1 and 4 cars (inclusive) are black.
4. No more than 3 cars are black.
5. More than 40 cars are not black.
Guessing I have to begin with n, x, p and q.
Thanks for the guidance.
1 solutions
Answer 370778 by scott8148(6628) on 2012-02-27 12:16:19 (Show Source):
You can put this solution on YOUR website!yes, you have to sum a few terms of the expansion (it shouldn't take "ages")
the expansion is ___ (Pb + Pn)^45 ___ (.22 + .78)^45
1. 43 (or less) are not black
___ subtracting the last 3 terms from one ___ 1 - {[(.78)^45] + 45[.22 (.78)^44] + 990[(.22)^2 (.78)^43]}
2. 45C6 [(.22)^6 (.78)^39] = .0572 (approx)
3. sum those four terms
4. see #1 ___ 42 (or more) are not black
5. see #3 ___ 4 (or less) are black
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Angles/578779: find the measure of an angle if its supplements measure 114 degrees less than 4 times its complement.
Im not able to figure this one out
1 solutions
Answer 370773 by scott8148(6628) on 2012-02-27 11:37:55 (Show Source):
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Equations/578760: How do i write the equation of a line that passes through (2,-9) and is perpendicular to the line (2x-9y=18)
1 solutions
Answer 370770 by scott8148(6628) on 2012-02-27 11:27:50 (Show Source):
You can put this solution on YOUR website!perpendicular means you can swap the x and y coefficients and change one of the signs
9x + 2y = ?
to find the new constant term, plug in the given point ___ 9(2) + 2(-9) = ? ___ 0 = ?
9x + 2y = 0
or, for those not comfortable with zero, ___ 2y = -9x ___ y = (-9/2)x
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Polygons/578764: how would you find the value of an angle inside a polygon?
1 solutions
Answer 370767 by scott8148(6628) on 2012-02-27 11:18:39 (Show Source):
You can put this solution on YOUR website!for regular polygons, the sum of the exterior angles is 360º
so, if n is the number of sides, one exterior angle is 360º divided by n
interior (inside) angles are supplementary to exterior angles (the pairs add to 180º)
so the value of an interior angle would be ___ 180 - (360 / n)
or ___ 180[(n - 2) / n]
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Functions/578734: I know what I pay for a case of water and I know what a distributor will sell it for. How do I calculate how much the distributor must buy it from me for if the distributor needs a 25% markup, 30% markup or 35% markup?
1 solutions
Answer 370749 by scott8148(6628) on 2012-02-27 09:38:38 (Show Source):
You can put this solution on YOUR website!for a 25% markup, the distributor's selling price (s) is 125% of the price he buys it for (b)
s = (125%)b ___ s = (1.25)b ___ s / 1.25 = b
the other values work the same way
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