Monday, August 5, 2013

Variable in Math and its Examples

We can define variable as a symbol or letter represents an unknown value. This means, the change of variable. Generally, we can show variable in math by the letters like x or y. For example, 5 x – 4 = 7, in this x is one of such. The number 5 is the coefficient of ‘x’ and 4, whereas 7 are the constant terms. We can define the kinds of these. They are Quantitative, qualitative, independent and dependant variables.
The Quantitative one means, always there is a change in numeric value. For example, Height, weight and age. Qualitative means, not having the particular order. For example, Names of persons may be peter or may be john or may be Emily or……..

Examples for solving for variables:
1. Find the value of the value of ‘ x, from the equation 3x – 7 = 9 – x.
Solution: The given equation is, 3x – 7 = 9 – x. To solve this, we can add + 7 on both sides. 3x – 7 + 7 = 9 + 7 – x which makes it 3x = 16 – x. Now, we can add the + x on both sides of the equation.      3x + x = 16 – x + x which makes it 4x = 16. Now, we can divide the equation by 4. Then the value of the given ‘ x is 4.

2. Find the value of the variable rates x, from the equation 14 – 3y = 4y.
Solution: The given equation is, 14 – 3y = 4y. To find the value of the unknown, we can Add + 3y on both sides of the equation. 14 – 3y + 3y = 4y + 3y or 14 = 7y. We can write this equation as 7y = 14. Then we can divide this equation by 7, we get y = 2. The value of the given ‘ y is 2.
3. Find the value of the value of ‘ r in the equation r – 4 + 6r = 3 + 8r.
Solution: r – 4 + 6r = 3 + 8r. First, we can add the - 8r on both sides of the equation. r – 4 + 6r – 8r = 3 + 8r – 8r. We get - r – 4 = 3. Then, we can add 4 on both sides, which makes it -r – 4 + 4 = 3 + 4 and - r = 7 and r = - 7.

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