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Equations/333892: im stuck!! and i dont know why but heres the question
3m-17=5m-1
1 solutions
Answer 239235 by jim_thompson5910(28598) on 2010-08-22 16:53:53 (Show Source):
You can put this solution on YOUR website!
 Start with the given equation.
 Add  to both sides.
 Subtract  from both sides.
 Combine like terms on the left side.
 Combine like terms on the right side.
 Divide both sides by  to isolate  .
 Reduce.
----------------------------------------------------------------------
Answer:
So the solution is
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Travel_Word_Problems/333890: find the adverage speed for the given distance and time. include the units of measure in your answer.
16. An airplane travels 775 miles in 120 minutes.
(I know that time goes into distance but i just dont understand the question) 1 solutions
Answer 239234 by jim_thompson5910(28598) on 2010-08-22 16:53:20 (Show Source):
You can put this solution on YOUR website!Since  , this means that  . Solve for r to get  . So the average speed is about 6.46 mi/min
Alternatively, 120 min = 2 hrs. So the average speed is also  mi/hr
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Unit_Conversion_Word_Problems/333885: Chemistry: conversions
An experiment requires that each student use an 8.5cm length of magnesium ribbon. How many students can do the experiment if theres a 570cm length of magnesium ribbon available.
I got 8.5cm x 570cm/ 1 student = 4845 but i know that cant be right..please help me 1 solutions
Answer 239231 by jim_thompson5910(28598) on 2010-08-22 16:35:42 (Show Source):
You can put this solution on YOUR website!If you had 8.5 cm of ribbon, then only  student can do the experiment. If you had 17 cm of ribbon, then  students can do the experiment.
So if you had 570 cm of ribbon, then  which means that about 67 students can do the experiment (round down to the nearest whole number).
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test/333886: Hi can you please help me with the following problem I am stuck.
Multiply
(8z - u)(3z + 4u)
Thanks 1 solutions
Answer 239230 by jim_thompson5910(28598) on 2010-08-22 16:33:19 (Show Source):
You can put this solution on YOUR website!
 Start with the given expression.
Now let's FOIL the expression.
Remember, when you FOIL an expression, you follow this procedure:
 Multiply the First terms:  .
 Multiply the Outer terms:  .
 Multiply the Inner terms:  .
 Multiply the Last terms:  .
---------------------------------------------------
So we have the terms:  ,  ,  ,
 Now add every term listed above to make a single expression.
 Now combine like terms.
So  FOILs to  .
In other words,  .
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Equations/333883: Please help me, I am soooo lost!
Find an equation of the line having given slope and containing the given point.
m = -8, (6, 8).
The equation of the line is y = ? 1 solutions
Answer 239229 by jim_thompson5910(28598) on 2010-08-22 16:28:26 (Show Source):
You can put this solution on YOUR website!If you want to find the equation of line with a given a slope of  which goes through the point (  ,  ), you can simply use the point-slope formula to find the equation:
---Point-Slope Formula---
 where  is the slope, and ) is the given point
So lets use the Point-Slope Formula to find the equation of the line
 Plug in  ,  , and  (these values are given)
 Distribute
 Multiply  and  to get
 Add 8 to both sides to isolate y
 Combine like terms  and  to get
So the answer is
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Linear-equations/333866: write the equation of the line that parallel to f(x)=3x-7 and goes through the point (0,4) 1 solutions
Answer 239228 by jim_thompson5910(28598) on 2010-08-22 16:26:52 (Show Source):
You can put this solution on YOUR website!Note:  is the same as
We can see that the equation  has a slope  and a y-intercept  .
Since parallel lines have equal slopes, this means that we know that the slope of the unknown parallel line is  .
Now let's use the point slope formula to find the equation of the parallel line by plugging in the slope  and the coordinates of the given point ) .
 Start with the point slope formula
 Plug in  ,  , and
 Distribute
 Multiply
 Add 4 to both sides.
 Combine like terms.
So the equation of the line parallel to  that goes through the point ) is  .
Here's a graph to visually verify our answer:
 Graph of the original equation  (red) and the parallel line  (green) through the point ) .
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Functions/333879: find the domain of the function g(x)=4/9-4x 1 solutions
Answer 239226 by jim_thompson5910(28598) on 2010-08-22 16:19:50 (Show Source):
You can put this solution on YOUR website!
 Start with the given function
 Set the denominator equal to zero. Remember, dividing by 0 is undefined. So if we find values of x that make the denominator zero, then we must exclude them from the domain.
 Subtract 9 from both sides
 Combine like terms on the right side
 Divide both sides by -4 to isolate x
 Reduce
Since  makes the denominator equal to zero, this means we must exclude  from our domain
So our domain is:
which in plain English reads: x is the set of all real numbers except x CANNOT equal
So our domain looks like this in interval notation
note: remember, the parenthesis excludes 9/4 from the domain
If we wanted to graph the domain on a number line, we would get:
 Graph of the domain in blue and the excluded value represented by open circle
Notice we have a continuous line until we get to the hole at  (which is represented by the open circle).
This graphically represents our domain in which x can be any number except x cannot equal 9/4
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test/333873: Hi I need some help with solving this story problem I can work it up to the end but I am not sure where to go from there, but here it is.
A launced rocket has an altitude, in meters, given by the polynomial h+xt-4.9t^2, where h is the height, in meters, from which the launch occurs, at velocity v in meters per second, and t is the number of seconds from which the rocket is airborne. If a rocket is launched from the top of a tower 60 meters high with an inital upward speed of 40 meters per second, what will its height be after 2 seconds.
I know the altitude h+vt - 4.9t^2
= 60 + vt - 4.9t^2
= 60 + 40t - 4.9t^2
= 60 + 40(2) - 4.9 (2)^2
60 + 40(2)-4.9(2)^2 = this is where I am not sure what to multiply add or subtract.
Please help me if you can and thanks :O)
1 solutions
Answer 239224 by jim_thompson5910(28598) on 2010-08-22 16:17:01 (Show Source):
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Average/333862: Algebra 2 test problem : a student scores on 5 test are 93%, 89%, 72%, 80% and 96% what must the student score on the 6th test so that the average is 88% .
I need the formula, I have the answer..
Thank u....;) 1 solutions
Answer 239216 by jim_thompson5910(28598) on 2010-08-22 15:26:07 (Show Source):
You can put this solution on YOUR website!Convert each percentage to decimal form to get 0.93, 0.89, 0.72, 0.80, and 0.96
Now let x = score on 6th test
So to find the average of the 6 tests, simply add them up and divide by 6 like so:
Now set that equal to the given average of 0.88 (88% in decimal form) to get
 Start with the given equation.
 Multiply both sides by 6.
 Multiply 0.88 and 6 to get 5.28
 Combine like terms.
 Subtract 4.3 from both sides.
 Combine like terms.
So the score on the 6th test must be a 98% (multiply 0.98 by 100 to convert it to a percentage) to get an average score of 88%
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Average/333860: If susan can pain a house in four hours, John can pain a house in six hours, and Peter can paint a house in ten hours. How long will it take if all of them painted the house together?
I tried averaging the numbers togther and then dividing it by three and sometimes its right and sometimes its wrong. Can you help? 1 solutions
Answer 239213 by jim_thompson5910(28598) on 2010-08-22 15:17:13 (Show Source):
You can put this solution on YOUR website!"If susan can pain a house in four hours", then she can paint  of a house in 1 hour. So her rate is  houses per hour.
If "John can pain a house in six hours", then he can paint  of a house in 1 hour. So his rate is  houses per hour.
Finally, if "Peter can paint a house in ten hours", then he can paint  of a house in one hour, making his rate  houses per hour.
So the three rates are:  ,  and  houses per hour.
Add them up to get
So their combined rate is  houses per hour. In other words, together they can paint  of a house in one hour (which is close to 1/2 of a house).
Now multiply this rate by some unknown time 't' to get  and set that equal to 1 (since we want to paint one house) to get
Next, multiply both sides by 60 to get  and then divide both sides by 31 to isolate t to get
So it will take them about 1.935 hours, or close to 2 hours, if they work together.
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Rectangles/333855: Find the perimeter of a square whose area is 144 inches square? 1 solutions
Answer 239206 by jim_thompson5910(28598) on 2010-08-22 15:04:10 (Show Source):
You can put this solution on YOUR website! Start with the area of a square formula.
 Take the square root of both sides (note: we're only taking the positive square root since a negative length doesn't make sense).
 Flip the equation.
 Plug in  (the given area).
 Take the square root of  to get  .
So if a square has an area of  square inches, then it has a side length of  inches.
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 Now move onto the perimeter of a square formula.
 Plug in  .
 Multiply  and  to get  .
So the perimeter of a square with a side length of  inches is  inches.
This means that if a square has an area of 144 square inches, this means that has a perimeter of 48 inches.
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Linear-equations/333721: Graph the linear equation
2x+4y=16
also find its x and y intercepts 1 solutions
Answer 239143 by jim_thompson5910(28598) on 2010-08-22 00:59:30 (Show Source):
You can put this solution on YOUR website!
x-intercept
To find the x-intercept, plug in  and solve for x
 Start with the given equation.
 Plug in  .
 Multiply  and 0 to get 0.
 Simplify.
 Divide both sides by  to isolate  .
 Reduce.
So the x-intercept is ) .
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y-intercept
To find the y-intercept, plug in  and solve for y
 Start with the given equation.
 Plug in  .
 Multiply  and 0 to get 0.
 Simplify.
 Divide both sides by  to isolate  .
 Reduce.
So the y-intercept is ) .
Now let's plot the points ) and ) which are the x and y intercepts respectively.
Now draw a straight line through the plotted points to graph  .
 Graph of
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Polynomials-and-rational-expressions/333720: what is t squared = 9t 1 solutions
Answer 239142 by jim_thompson5910(28598) on 2010-08-22 00:57:42 (Show Source):
You can put this solution on YOUR website!
 Start with the given equation.
 Subtract 9t from both sides.
Notice that the quadratic  is in the form of  where  ,  , and
Let's use the quadratic formula to solve for "t":
 Start with the quadratic formula
 Plug in  ,  , and
 Negate  to get  .
 Square  to get  .
 Multiply  to get
 Subtract  from  to get
 Multiply  and  to get  .
 Take the square root of  to get  .
 or  Break up the expression.
 or  Combine like terms.
 or  Simplify.
So the solutions are  or
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Distributive-associative-commutative-properties/333713: Factor.
12x^2+xy-6y^2
1 solutions
Answer 239141 by jim_thompson5910(28598) on 2010-08-21 23:50:37 (Show Source):
You can put this solution on YOUR website!
Looking at the expression  , we can see that the first coefficient is  , the second coefficient is  , and the last coefficient is  .
Now multiply the first coefficient  by the last coefficient  to get  .
Now the question is: what two whole numbers multiply to  (the previous product) and add to the second coefficient  ?
To find these two numbers, we need to list all of the factors of  (the previous product).
Factors of  :
1,2,3,4,6,8,9,12,18,24,36,72
-1,-2,-3,-4,-6,-8,-9,-12,-18,-24,-36,-72
Note: list the negative of each factor. This will allow us to find all possible combinations.
These factors pair up and multiply to  .
1*(-72) = -72
2*(-36) = -72
3*(-24) = -72
4*(-18) = -72
6*(-12) = -72
8*(-9) = -72
(-1)*(72) = -72
(-2)*(36) = -72
(-3)*(24) = -72
(-4)*(18) = -72
(-6)*(12) = -72
(-8)*(9) = -72
Now let's add up each pair of factors to see if one pair adds to the middle coefficient  :
| First Number | Second Number | Sum | | 1 | -72 | 1+(-72)=-71 | | 2 | -36 | 2+(-36)=-34 | | 3 | -24 | 3+(-24)=-21 | | 4 | -18 | 4+(-18)=-14 | | 6 | -12 | 6+(-12)=-6 | | 8 | -9 | 8+(-9)=-1 | | -1 | 72 | -1+72=71 | | -2 | 36 | -2+36=34 | | -3 | 24 | -3+24=21 | | -4 | 18 | -4+18=14 | | -6 | 12 | -6+12=6 | | -8 | 9 | -8+9=1 |
From the table, we can see that the two numbers  and  add to  (the middle coefficient).
So the two numbers  and  both multiply to and add to
Now replace the middle term  with  . Remember,  and  add to  . So this shows us that  .
 Replace the second term  with  .
 Group the terms into two pairs.
 Factor out the GCF  from the first group.
 Factor out  from the second group. The goal of this step is to make the terms in the second parenthesis equal to the terms in the first parenthesis.
 Combine like terms. Or factor out the common term
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Answer:
So  factors to  .
In other words,  .
Note: you can check the answer by expanding  to get  or by graphing the original expression and the answer (the two graphs should be identical).
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