Friday, December 21, 2012

Variable Pairs


Variable pairs determines the concept of an ordered pair and it shows you to plot ordered pairs  on a graph. The variable determine the value of the particular terms of the equation.

The variable pair is a set of two variable like (x, y) written in parentheses. The variable in terms of graph represent the first value as x and the second value as y. (2,3) represents x axis is 2 units long and y axis is 3 units long.

Example Problem for Variable Pairs:

Solve for the ordered pair from the following equations:

4x + 3y = 12

2x + 3y =  8 solve for x and y

Solution:

Given that 4x + 3y = 12--------------------- (1)

2x + 3y =   8--------------------- (2)

Subtract the first equation and second equation,



4x + 3y = 12

2x + 3y =   8

________________

2x  = 4

________________

That is

4x – 2x = 2x

3y – 3y = 0

12 – 8   = 4

Now we have the equation 2x = 4 after subtraction.

2x = 4

Divide by 2 on both sides

x = `4 / 2`

x = 2

Substitute the x = 2 in the first equation, we will get the value of y variable.

First equation 4x + 3y = 12

4(2) + 3y = 12

8 + 3y = 12

3y = 12 – 8

3y = 4

y = `4 / 3`

The solution is x = 2 and y = `4 /3` .

My forthcoming post is on Exponential Data Sets and Exponential Differentiation will give you more understanding about Algebra.

Example Problem for Variable Pairs:

Solve for the ordered pair from the following equations:

8x + 2y = 4

x + 3y =   5

Solution:

Given that 8x + 2y = 4--------------------- (1)

x + 3y =   5--------------------- (2)

Subtract the first equation and second equation,

3 * (1)    24x + 6y = 12

2 * (2)      2x + 6y =-10

________________

22x   = 22

________________

That is

24x – 2x = 22x

6y – 6y = 0

12 – (-10)  = 22

Now we have the equation 22x = 22 after subtraction.

Divide by 22 on both sides. we get

x = 1

Substitute the x = 22 in the first equation,

First equation 8x + 3y = 4

8(22) + 3y = 4

176 + 3y = 4

3y = 4 – 176

3y = -172

y = `-172 / 3`

The solution is x = 1 and y = -`172 /3` .

The value of variable pairs (x,y) is (1,-`172/3` )

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