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Square-cubic-other-roots/333131: The formula v=square root of 20L can be used to estimate the speed of a car, v, in miles per hour, based on the length, L, in feet, of its skid marks upon sudden braking on a dry asphalt road. If a car is involved in an accident and its skid marks measure 405 feet, at what estimated speed was the car traveling when it applied its brakes just prior to the accident?
Show your work. 1 solutions
Answer 238688 by vleith(2825) on 2010-08-19 15:24:03 (Show Source):
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expressions/333014: Find three ordered pairs that satisfy the equation.
y = -3x + 5 1 solutions
Answer 238618 by vleith(2825) on 2010-08-19 06:46:50 (Show Source):
You can put this solution on YOUR website!Just plug and play.
Pick a value for x, then use that value of x to find y
for instance, pick x = 0

So one ordered pair is (0,5)
Pick another value for x. Let's pick x = 1

A second ordered pair is (1,2)
Use the same process to find as many ordered pairs as you want
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Evaluation_Word_Problems/332749: MAN JUMPS 3 FENCES TO AN APPLE TREE HE PICKS APPLES ON THE WAY BACK HE MUST GIVE EACH FARMER AT THE FENCE 1/2 OF WHAT HE HAS + 1/2 AN APPLE AFTER ALL 3 FENCES HE'S LEFT WITH ONE HOW MANY DID HE START WITH 1 solutions
Answer 238425 by vleith(2825) on 2010-08-18 07:48:16 (Show Source):
You can put this solution on YOUR website!Do this one backwards
After the last fence, he has 1 apple.
Before the fence he had x apples
You are told
 so he hads 3 apples before the last fence.
Now go back to fence 2
 He had 7 apples before he hopped the second fence
Now all the way back to the fence closest to the tree

He started with 15 apples
He had to give 8 apples to the first farmer
4 apples to the second farmer
2 apples to the last farmer
and he ges one lousy apple for all his hard work and fence jumping
I hope it was worth it.
How about THEM apples :)
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Probability-and-statistics/332750: a student has to answer 10 questions, choosing at least 4 from each of part A and part B. If there are 6 questions in part A and 7 in part B, in how many ways can the student choose 10 questions ? 1 solutions
Answer 238424 by vleith(2825) on 2010-08-18 07:42:02 (Show Source):
You can put this solution on YOUR website!Let's pick from type A first.
We need to pick 4.
First pick has 6 choices
Second one now has 5
Third 4
Fourth 3
That leaves 2 extra type As
Now let's pick 4 from type B
Fifth pick has 7 choices
Sixth has 6
Seventh 5
Eight 4
That leaves 3 more type B.
We have two more picks to make and 5 question left to pick from
Ninth has 5 choices
Tenth has 4
Now, do the math

Solve that and there you go!
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Equations/332530: x^2-16<= 0 1 solutions
Answer 238288 by vleith(2825) on 2010-08-17 11:55:59 (Show Source):
You can put this solution on YOUR website!Find the roots.

root at x = 4 and x = -4
Now pick a value less than -4. let's say -10.
When x=-10, then  which is > 0
Pick a value between the two root. Say x=0
When x=0  which is < 0
Pick a value greater than 4, say 10
Again  which is greater than 0.
So points to the left of -4 and to the right of 4 do not satisfy the inequality.
The plot will be all points above the curve x^2-16 and below the x axis, between -4 and 4
See this URL for a plot
http://www.wolframalpha.com/input/?i=x^2-16%3C%3D0
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test/331487: I have asked for help on this story problem before however I have never heard back so I am still need of some help with solving this story problem.
In 1991 the life expectancy of males in a certain country was 63.2 years. In 1996 it was 65.7 years. Let E represent the life expectancy in year t, and let + represent the number of years since 1991.
The linear function E(t) that fits the data is E)t)=_____t + _____.
Use the function to predict the life expectancy of males in 2006.
E (15)= _____ and round to the nearest tenth.
Thanks for your help :o) 1 solutions
Answer 237605 by vleith(2825) on 2010-08-13 06:37:37 (Show Source):
You can put this solution on YOUR website!Use the info provided to create a linear model of Life Expenctency.
You are given two points. With that data you have enough information to create the equation for a line.
First let's find the slope of the line
Slope = 
You are given the two data points (1991,63.2) and (1996, 65.7)
So the slope is  = 
The problem says to model the Life Expectancy where t is the 'number of years since 1991"
So
 that uses the slope we found above as the rate of change year to year. It also uses the expectency in the year 1991 as the starting point.
Check this now. In year 1991, t = 1991-1991 = 0. So  which is correct
IN 1996, t = 1996-1991 = 5. So  which is correct
You are then asked to use the equation to extrapolate the data to the year 2006
So, 2006-1991 = 15
Again, this is just a model. There is nothing to suggest that Life expectency is linear. But that is all the data you have, so you have to go with that.
Make sense?
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expressions/331327: solve the formula for the indicated letter
x = w+y+z
-------- for y
5
I am confused on how to do this problem. Please help 1 solutions
Answer 237459 by vleith(2825) on 2010-08-12 16:01:37 (Show Source):
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Radicals/331330: Simplify by factoring, assume that all expressions under the radical represent non-negative numbers.
Please show each step? Thank you.
∜(162x^4 y^6 )
Thank you again 1 solutions
Answer 237458 by vleith(2825) on 2010-08-12 16:00:13 (Show Source):
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Equations/331324: solve using addition and multiplication principles
4n - 24(less than or = to)3 (4n + 8)
I did not know how to type this < with a line under it so I just wrote it out. 1 solutions
Answer 237451 by vleith(2825) on 2010-08-12 15:49:06 (Show Source):
You can put this solution on YOUR website! expand
 collect like terms
 isolate variable
 remember to flip the sign when dividing or multiplyig an inequality by a negative number
see here for a plot
http://www.wolframalpha.com/input/?i=4n+-+24+%3C%3D+3+%284n+%2B+8%29
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