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unlockmath answered: 1598 problems
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Volume/697496: a square room with a height of 4 meter has its 4 walls of an area of 96 sq meters. what is the dimension of the room
1 solutions
Answer 430161 by unlockmath(1599)   on 2012-12-31 20:45:49 (Show Source):
You can put this solution on YOUR website!Hello,
One wall has a width of 4 meters. Why? Because 4*6=24 sq meters of one wall so
4 times 24 = 96 sq meters
Now we know the the dimensions are:
6 meters by 6 meters by 4 meters
Make sense?
RJ
www.math-unlock.com
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Expressions-with-variables/697602: the cost of 4 pairs of shoes and 6 pairs of sneakers is $64. If the price of the shoes were increased by 10% and that of the sneakers by 5%, the total cost would be $69.80. find the original price of a pair of shoes.
1 solutions
Answer 430159 by unlockmath(1599) on 2012-12-31 20:34:25 (Show Source):
You can put this solution on YOUR website!Hello,
Let's set up two equations with x represents the cost of shoes and y represents cost of sneakers:
4x+6y=64
[1.10(4x)+1.05(6y)=69.80]
Multiply the second equation by 100 to get:
110(4x)+105(6y)=6980
Expand this to:
440x+630y=6980
Now take the first equation multiply it by -110 to get:
-440x-660y=-7040
Add this equation to the second to get:
-30y=-60
Divide by -30 to get:
y=2
x=13
So a pair of shoes cost $13, pretty cheap, huh?
Make sense?
RJ
www.math-unlock.com
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percentage/697425: what is a 20% discount off of $945.00 ?
1 solutions
Answer 429972 by unlockmath(1599) on 2012-12-30 15:54:54 (Show Source):
You can put this solution on YOUR website!Hello,
(Hint: once we understand the meaning of "off of" then the problem is simple.
So multiply:
.20 * 945 = $189
This is the money we save on the discount.
We can go a step further and find the price we'll pay:
Now subtract this from the total:
$756.00
RJ
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Length-and-distance/697379: Which is a equation of a line parallel to the line whose equation is 3y=2x+3
A. 3y=-2x+1
B.y=2/3x+3
C.y=3/2x-3
D.2y=2x+3
1 solutions
Answer 429971 by unlockmath(1599) on 2012-12-30 15:46:35 (Show Source):
You can put this solution on YOUR website!Hello,
Couple ways to solve this:
Put 3y=2x+3 in Slope-intercept form as:
y=2/3x+1
Now that we know the slope of the line is 2/3, that gives us only one equation the has the same slope:
B.y=2/3x+3
Make sense?
RJ
www.math-unlock.com
|
Geometry_Word_Problems/697103: The lenghts of the sides of a tringle are consecutive odd numbers. Find the lenghts of the sides if the perimeter is 7cm less than 4 times the shortest sides?
1 solutions
Answer 429662 by unlockmath(1599) on 2012-12-28 00:21:39 (Show Source):
You can put this solution on YOUR website!Hello,
Let x represent an odd number. Next is x+2 and x+4.
Now we can set up an equation as:
x+x+2+x+4=4x-7
Solve:
3x+6=4x-7
Subtract 3x and add 7 to get:
13=x
Now we know the sides are:
13 cm
15 cm
17 cm
Make sense?
RJ
www.math-unlock.com
|
Numeric_Fractions/696974: please help me solve this fraction: 15 7/8 - 3/9.
my solution: 15 7/8 (9/9) - 3/9 (8/8)= 15 63/72 - 24/72= 15 39/72.... now I'm stuck. please help!
1 solutions
Answer 429555 by unlockmath(1599) on 2012-12-26 22:47:18 (Show Source):
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test/696042: Car travels 70.5 miles on 3gal of gas. Find the distance that the car travel on 14 gal of gas
1 solutions
Answer 428755 by unlockmath(1599) on 2012-12-19 19:37:04 (Show Source):
You can put this solution on YOUR website!Hello,
Let's use proportions for this problem.
70.5/3 = x/14
Cross multiply:
3x = 987
Divide by 3:
329 miles
Make sense?
RJ
www.math-unlock.com
|
Angles/695955: Two vertical angles measure 2x-12 and 5x-12. Find the size of one of these vertical angles
1 solutions
Answer 428720 by unlockmath(1599) on 2012-12-19 15:15:48 (Show Source):
You can put this solution on YOUR website!Hello,
Since vertical angles equal each other we can set up the following:
2x-12 = 5x-12
Add 12 and subtract 2x to get:
0 = 3x
Divide 3 and we get:
x=0 degrees
RJ
www.math-unlock.com
|
Word_Problems_With_Coins/695616: how many nickles and quaters are in 5.80 if there are 60 coins?
1 solutions
Answer 428565 by unlockmath(1599) on 2012-12-18 15:08:12 (Show Source):
You can put this solution on YOUR website!Hello,
Let's have N represent nickles and Q be quarters so we can set up 2 equations:
N + Q = 60 or can be written as: N= 60-Q
.05N +.25Q = 5.80
With me so far?
Let's get rid of the decimals by multiplying by 100:
5N + 25Q = 580
Now, let's use substitution:
5(60-Q)+25Q=580
Expand:
300-5Q+25Q=580
Subtract 300:
20Q=280
Divide by 20:
Q=14
So we know that there are 14 quarters and 46 nickles.
Make sense?
RJ
www.math-unlock.com
|
Linear-systems/694791: state whether the equation is linear or not 2x+y=11
1 solutions
Answer 428199 by unlockmath(1599) on 2012-12-16 12:35:25 (Show Source):
You can put this solution on YOUR website!Hello,
It's linear. (Hint: Look at the word linear. Drop the last two letters -ar and what word is it? Line)
Equations with 2 variables (for example x & y)that are not to a power (like x^2) are all linear equations. They all form a straight line when graphed.
Make sense?
RJ
www.math-unlock.com
|
Percentage-and-ratio-word-problems/694456: i need help in this question that i have. Can you please help. it says: A car travels 440 miles in 8 hours. Write and solve a proportion to determine the average speed of the car.
1 solutions
Answer 427948 by unlockmath(1599) on 2012-12-14 22:19:43 (Show Source):
You can put this solution on YOUR website!Hello,
We know speed equals miles divided by time.
So we can plug in the values and solve:
440/8 = 55 miles per hour
To set this up as a proportion:
440/8 = x/1 hour
Cross multiply:
440=8x
Divide by 8 and we get:
55 mph
Make sense?
RJ
www.math-unlock.com
|
Rectangles/694465: A rectangle has an area of 54 feet. The length of the rectangle is three feet more than twice the width. Use factoring method to determine the length and width of the rectangle
1 solutions
Answer 427947 by unlockmath(1599) on 2012-12-14 22:12:30 (Show Source):
You can put this solution on YOUR website!Hello,
Let width be represent by x and length be 3+2x.
The equation would look like this:
2x+2(3+2x)=54
Rewritten as:
2x+6+4x=54
6x=48
x=8
Now we know the width is:
8 feet
Length is:
19 feet
Got it?
RJ
www.math-unlock.com
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Finance/694460: I am looking to go back to college and I have been out of Math for about 10 years. Needless to say I have forgotten how to do a lot of it. Do you have any good ideas on what I should do to get back into quick as there is a lot of material.
1 solutions
Answer 427946 by unlockmath(1599) on 2012-12-14 22:07:10 (Show Source):
You can put this solution on YOUR website!Hello,
Check out my website www.math-unlock.com
I wrote a book on the basics of math that is not found in math books. It's the rock bottom of math and gives a great foundation to jump back into the vast subject.
RJ
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Equations/694462: The length of a rectangle is 4cm more than twice the width. The perimeter is 92cm. What are the dimensions of the rectangle?
1 solutions
Answer 427945 by unlockmath(1599) on 2012-12-14 22:05:03 (Show Source):
You can put this solution on YOUR website!Hello,
Let width be represented by x and length be represented by:
4+2x
Now we can set up the equation as:
2x+2(4+2x)=92
2x+8+4x=92
6x=84
x=14
Now we know what x is so plug in the value to each side:
Width is 14 cm
Length is 32 cm
Make sense?
RJ
www.math-unlock.com
|
Linear_Equations_And_Systems_Word_Problems/694021: The sum of two number is 1. Four times the first number equals 2 times the second number. Find the two numbers.
1 solutions
Answer 427699 by unlockmath(1599) on 2012-12-13 17:30:34 (Show Source):
You can put this solution on YOUR website!Hello,
Let's use x & y for the unknowns for the 2 equations:
x + y = 1
4x = 2y
Let's use substitution:
x=1-y
Plug this into the second equation:
4(1-y)=2y
Expand:
4-4y=2y
Add 4y and divide by 6 toget:
y= 4/6 or 2/3
So we know from the first equation:
x= 1/3
Make sense?
RJ
www.math-unlock.com
|
Travel_Word_Problems/693778: How far could Jim run if he ran 20 mph for 10 min
1 solutions
Answer 427598 by unlockmath(1599) on 2012-12-13 10:21:46 (Show Source):
You can put this solution on YOUR website!Hello,
Let's first change 10 minutes to an hour. This would be 10/60 or 1/6 hour.
Now we can solve this problem.
If the person can run 20 miles in one hour. (20 mph)
Then multiply 1/6 * 20 and we get:
20/6 or 3 1/3 miles
Make sense?
RJ
www.math-unlock.com
|
Geometry_Word_Problems/693464: Find the area of an equilateral triangle given a side length of 8 in.
1 solutions
Answer 427424 by unlockmath(1599) on 2012-12-12 14:51:10 (Show Source):
You can put this solution on YOUR website!Hello,
First, let's find the height by using:
A^2+4^2=8^2
Rewritten as:
A^2=48
A=sq rt 48
Now we can use the area of a triangle:
1/2*4*sq rt 48 to get:
2 sq rt 48 or rewritten as:
4 sq rt 12 square inches
make sense?
RJ
www.math-unlock.com
|
Travel_Word_Problems/692315: Bill can mow a lawn in 1 1/2 hours with a riding lawn mower. Joe can mow it in 2 1/2 hours with a push mower. How long should it take to do the job if they work together? (HINT: Rates add. Rate(Bill) + Rate(Joe) = Rate(together) and rate is amount mowed divided by time taken.)
1 solutions
Answer 426967 by unlockmath(1599) on 2012-12-10 12:00:09 (Show Source):
You can put this solution on YOUR website!Hello,
We can use the following equation:
x/1.5 + x/2.5 = 1
Multiply by 15 to get:
10x + 6x = 15
Combine and divide by 16:
x= 15/16 of an hour.
Make sense?
RJ
www.math-unlock.com
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