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Linear-systems/255829: how do i find the equation of a line through two points, (4,3) and (2,4)? Please explain, the book says the answer is y=-1/2x+5 but I don't get how they got -1/2 and 5.
1 solutions
Answer 188068 by richwmiller(9135)   on 2010-01-11 18:54:27 (Show Source):
You can put this solution on YOUR website!-1/2=m
5=b
y=mx+b
y-y1=m*(x-x1)
where m=slope the -1/2
(4-3)=m*(2-4)
1/-2=-1/2=m
y=mx+b
now choose either point.
4=-1/2*2+b
4=-1+b
5=b
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Points-lines-and-rays/255807: In the diagram, ABCDE is a regular pentagon with the measure of represented by 2x + 1. If the perimeter of the pentagon is 45, find the value of x.
1 solutions
Answer 188061 by richwmiller(9135) on 2010-01-11 18:41:25 (Show Source):
You can put this solution on YOUR website!Reminder :
Website rules
One question per submission.
4 questions daily
No similar questions
A regular pentagon has 5 equal sides.
45/5=9
Unfortunately, you didn't say what 2x+1 represents.
If 2x+1 is one side the 2x+1=9
2x=8
x=4
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Functions/255797: Please help me with this...
For all x=-4, which of the following is equivalent to the expression below?
x2 + 12x +32
-------------------
x+4
1 solutions
Answer 188040 by richwmiller(9135) on 2010-01-11 18:12:40 (Show Source):
You can put this solution on YOUR website!You forgot to include "the following"
If x=-4 in the expression then the expression is undefined since division by 0 is undefined.
 =  =  except when 
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Numbers_Word_Problems/255763: The difference between two numbers is six and a half,the sum of the numbers is one more than the square root of their product. What is the smaller number?
1 solutions
Answer 188030 by richwmiller(9135) on 2010-01-11 17:24:14 (Show Source):
You can put this solution on YOUR website!a-b=6.5
a+b=1+sqrt(ab)
I find it hard to believe that this could be right.
The difference (first equation) tells us that the numbers are not integers.
But the answers from my equations are all complex numbers involving i.
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Exponents/255753: I have trouble with homework I need help I have to collect like terms and I forgot how to do it. 5x^3+8x^3+3=
1 solutions
Answer 188018 by richwmiller(9135) on 2010-01-11 16:58:47 (Show Source):
You can put this solution on YOUR website!You don't have to add all the drama . Everyone here wants help with their homework and don't know how tom do it.
Here is an example of collecting like terms.
4a+2a=6a
Look at x^3 as if it were the a above
5(x^3)+8(x^3)+3=
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Numbers_Word_Problems/255749: When a number is diminished by its opposite, the result is 12. Find the number.
1 solutions
Answer 188013 by richwmiller(9135) on 2010-01-11 16:51:17 (Show Source):
You can put this solution on YOUR website!Your first problem is a fun trick.
A number added to its opposite is 0.
6+(-6)=0
So if you are diminishing by its opposite you are doubling it.
6-(-6)=12
Sorry but you are limited by the website rules to one question per submission and limited to 4 problems daily and also no similar problems.
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Exponents/255738: a. Simplify the following expressions. (-1)^1, (-1)^2, (-1)^3, (-1)^4, (-1)^5/
b. What is the sign of the final answer when the exponent is odd? When the exponent is even?
c. Use your answer from part (b) to simplify (-1)^19.
1 solutions
Answer 188011 by richwmiller(9135) on 2010-01-11 16:43:24 (Show Source):
You can put this solution on YOUR website!1 times 1 is 1 the only question is which sign.
When the number (-1) is raised to an even power (exponent) the sign is positive and when the power is odd the sign is neqative.
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Triangles/255680: The measures of the two acute angles in a right triangle are in the ratio 2:3. What is the measure of the smallest angle of the triangle?
1 solutions
Answer 187906 by richwmiller(9135) on 2010-01-11 12:39:14 (Show Source):
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Angles/255668: Write and solve an equation to find the angle, its complement, and its supplement in this problem: The supplement of angle is 36 degrees less than three times its complement.
1 solutions
Answer 187903 by richwmiller(9135) on 2010-01-11 12:34:57 (Show Source):
You can put this solution on YOUR website!a+s=180
s=180-a
a+c=90
c=90-a
s=-36+3c
substitute 180-a for s
substitute 90-a for c
180-a=36+3*(90-a)
I leave the solving to you
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percentage/255673: What is the equation of the line that contains the points with (x,y) coordinates (–3,7) and (5,–1) ?
1 solutions
Answer 187899 by richwmiller(9135) on 2010-01-11 12:27:57 (Show Source):
You can put this solution on YOUR website!-1-7=(5-(-3))*m
-8=8m
-8/8=m
-1=m
y-7=-1(x-(-3)
y-7=-1x-4*3
y-7=-x-12
y=-x-5
This lines slant down from left to right.
when x=0 y=-5
when y=0 x=-5
BTW There are an infinite number of lines with those x's and y's not just one.
So the question should have been "What is an equation of a line etc?"
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Rectangles/255639: One side of a rectangle is (2x - 3) metres.
The perimeter of the rectangle is 50 metres.
(a) Show that the area, A, of the rectangle is given by
A=62x-84-4x(squared)
The area of the rectangle is 126m(squared)
1 solutions
Answer 187890 by richwmiller(9135) on 2010-01-11 12:09:59 (Show Source):
You can put this solution on YOUR website!2*(2x-3)+2W=50
4x-6+2W=50
2w=50+6-4x
w=25+3-2x
width=w=28-2x
length=2x-3
A=62x-84-4x^2
-2(x-14)*(2x-3)
(2x-3)*(-2)*x-14)
(2x-3)(-2x+28)
(2x-3)(28-2x)
length=2x-3
width =28-2x
They are equal therefore A=62x-84-4x^2
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Miscellaneous_Word_Problems/255657: Stacy has a collection of coins from 5 diffrent countries. Half of the coins are from England, 1/6 are from Mexico, 1/6 are from India, 1/12 are from Italy, and 7 are from Spain. How many coins are in the collection, and how many are from each country?
1 solutions
Answer 187883 by richwmiller(9135) on 2010-01-11 11:46:55 (Show Source):
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Radicals/255659: 80. Find all real or imaginary solutions to each equation. Use the method of your choice. w2=-225
30. Solve each equation by using the quadratic formula. -3x^2-2x-5=0
1 solutions
Answer 187880 by richwmiller(9135) on 2010-01-11 11:38:11 (Show Source):
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Linear-systems/255664: what is a system equation and how do you solve?
1 solutions
Answer 187878 by richwmiller(9135) on 2010-01-11 11:33:58 (Show Source):
You can put this solution on YOUR website!system of equations means more than one equation with the same variables.
There are three common ways of solving them.
graphing
substitution (find the value of one in terms of the other and substitute that for the one.) Sounds worse than it is.
elimination (adding , multiplying them )
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Parallelograms/255640: If you have a parallelogram with two lines bisecting. with m+9.1 on one half of the bisector and 4k-3.5 on the other side. and on the other line there is 2.6k and m. How do you solve this without having to deal with 2 variables?
1 solutions
Answer 187873 by richwmiller(9135) on 2010-01-11 11:27:22 (Show Source):
You can put this solution on YOUR website!Let's look at what we know before we panic.
Since the line bisects it creates two equal parts.
m+9.1=4k-3.5
oh no we have one equation with two variables.
Stay calm; we aren't finished yet.
2.6k=m
Oh now we have two equations with two variables. So we can solve the two equations and find out where they intersect.
Well, look at that m=2.6k
We can substitute 2.6k for m in the first equation.
2.6k+9.1=4k-3.5
We now have one equation with one variable.
Panic attack avoided.
k=9
2.6k=m
2.6*(9)=m
23.4 = m
We can check.
23.4+9.1=4(9)-3.5
32.5=32.5
ok
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Exponents/255642: How do you solve:
(x^10*y^(-8))^-3
that is x to the exponent of 10; y to the exponent of -8; and all of it to the -3
1 solutions
Answer 187868 by richwmiller(9135) on 2010-01-11 11:00:35 (Show Source):
You can put this solution on YOUR website!Very interesting problem. Easy solution.
The important thing to remember is negative exponent means the reciprocal.
 = 
 =  = 
We have reciprocals of reciprocals in your problem.
 = 
so
=
 =
 =
Let's deal with the reciprocal now
 =
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Percentage-and-ratio-word-problems/250092: The will of an eccentric millionaire reads as follows: "I leave 4/17 of my estate to my son, 7/13 of the remainder to my wife, 2/3 of this remainder to my daughter, and the remaining $2 million to my dog." What was the total amount of the estate?
1 solutions
Answer 187816 by richwmiller(9135) on 2010-01-11 07:57:28 (Show Source):
You can put this solution on YOUR website!w=a+b+c+2 000 000
a=4w/17
b=7/13*(17w/17-4w/17)=7/13*13w/17=7w/17
c=2/3(w-4w/17-7w/17)=2/3*(w-11w/17)=2/3*6w/17=4w/17
w=4w/17+7w/17+4w/17+2,000,000
w=15w/17+2 000 000
2w/17=2 000 000
2w=34 000 000
w=$17,000,000
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Geometry_Word_Problems/255593: A certain right triangle has its area numerically equal to its perimeter. The length of each side is an even integer. What is the perimeter?
(1) 26 (2) 28 (3) 30 (4) 32 (5) None of the above
1 solutions
Answer 187813 by richwmiller(9135) on 2010-01-11 07:25:59 (Show Source):
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Linear-equations/255588: Find the slope, if it exists.
-2x+y=8
If I'm using Slope Intercept Form (y=mx+b), m being slope, x being the variable you need to solve for, and b being the y intercept, is -2 the slope (m)?
1 solutions
Answer 187809 by richwmiller(9135) on 2010-01-11 07:15:08 (Show Source):
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