Wednesday, December 2, 2009
Elementary Algebra, ratio word problems
Question:-
Find two numbers such that their difference ,sum and product are in the ratio 1:4:15 respectively.
Answer:-
This solution will explain how to understand ratio word problems
Let the numbers be x and y
By the problem
(x-y) : (x+y) : (xy) = 1 : 4 : 15
x-y = k ----- 1
x+y = 4k ----- 2
xy = 15k -------- 3
Where k is the constant of proportionality
From 1+2 , we get x = 5k/2
Substitute this in eq 2 , we get y = 3k/2
By substituting this x and y values in eq 3
We get k = 4
If we put this k value in x = 5k/2 , we get x = 10
If we put k value in y = 3k/2 , we get y = 6
So the numbers are 10,6
Wednesday, August 26, 2009
How to find Slope of parallel lines
is undefined meaning it has "no slope."
Question:-
How to find the slope of the line parallel to x+2y=10
Answer:-
Point to remember:- Parallel lines will have same slope
So we just have to find the slope of the given line.
x+2y = 10
subtract 'x' on both sides
2y = -x+10
divide by 2 on both sides
y = -x/2 + 5
So the slope is -1/2 for both the lines.
same way,we can also find all points having an x-coordinate of 2 whose distance from the point 2 1 is 5
Thursday, August 20, 2009
What is a Natural number
In mathematics, from number theory tutorial there are two conventions for the set of natural numbers: it is either the set of positive integers {1, 2, 3, ...} according to the traditional definition or the set of non-negative integers {0, 1, 2, ...} according to a definition first appearing in the nineteenth century.
Natural numbers have two main purposes: counting ("there are 3 apples on the table") and ordering ("this is the 3rd largest city in the country"). These purposes are related to the linguistic notions of cardinal and ordinal numbers, respectively. (See English numerals.) A more recent notion is that of a nominal number, which is used only for naming.
Properties of the natural numbers related to divisibility, such as the distribution of prime numbers, are studied in number theory. Problems concerning counting and ordering, such as partition enumeration, are studied in combinatorics.
When we add two natural numbers
we also get a natural number
Let's have a look at a simple problem from numeric and algebraic operations
2 is a natural number
5 is also natural number
2+5=7
7 is also a natural number.
We represent natural numbers with W
w={ 0,1,2,3.....}
If you know the basics of this you can get any math answers
Wednesday, August 19, 2009
How to convert Decimal into Fraction
A fraction is a mathematical expression relating two quantities or numbers, one divided by the other. The numbers may be whole numbers integers- this is a rational number. For example, 1/2 is a fraction. They can also be polynomials - this is a rational function.
Let's have a look at the answer which have done by online algebra tutor
Here is example of a 7th grade math equations
For similar problems of this type purple math will guide you.
Wednesday, August 12, 2009
Rules of Exponents
Exponentiation is a mathematical operation, written an, involving two numbers, the base a and the exponent n. When n is a positive integer, exponentiation corresponds to repeated multiplication:
Here are some examples:
1.)Addition:An exponent can be added only when they have the same number.
For example: 2x1 + 2x1 = 4x1
3x2 - 2x2 = 5x2
2.)Subtraction:The rule is same for subtraction.
3.)Multiplication:While multiplying, multiply the numbers and add the exponents.
For example: 3x1 * 2x1 = 6x2 (Add)
4x2 * 3x3 = 12x5 (Add)
4.)Division:While dividing the exponents, the denominator takes the opposite sign and m
and mover to the numerator. The numbers should be divided as usual.
For example:
36x8-4
___________ = 6x4
64
48x2+4
___________ = 8x6
6x-4
For more help on this. you can contact us.
Tuesday, July 28, 2009
Friday, July 17, 2009
problem on simple interest
Interest is a fee paid on borrowed assets. It is the price paid for the use of borrowed money or, money earned by deposited funds. Assets that are sometimes lent with interest include money, shares, consumer goods through hire purchase, major assets such as aircraft, and even entire factories in finance lease arrangements.
Let's see a problem on this.
Question:
Greg invests $1200 at an annual rate of 6.5%. How long will it take until Greg earns $195 in interest?
Solution:
Formula to find the interest is
For more help on this ,you can reply me.
I = PTR/100
here p = profit=1200
t = time
r = rate=6.5
Substitute the values in formula,so that
(1200 x T x 6.5)
195 = -----------------
100
T = 2.4
Greg will earn $195 in interest in 2.5 years.