Vriable of Math

Introduction to variable of math:

A variable is a symbol that stands for a value that may vary; the term usually occurs in opposition to constant, which is a symbol for a non-varying value, i.e. completely fixed or fixed in the context of use. The concepts of constants and variables are fundamental to all modern mathematics, science, engineering, and computer programming. Please express your views of this topic Functions Math by commenting on blog.


Example problems of variable in math:


Variable of math problem 1:

James, Mickel and John are friends. James’s age is one-third of Mickel and John is five years elder than Mickel. If the sum of the age of the friends is 40, find the ages of each one.

Sol:

From the statement,

Age of Mickel= x

Age of James   `=x/3 `

Age of John = x+5

Sum of the ages=40.

`x/3 + x+x+5= 40`

`(7x+15)/3 =40`

Multiplying by 3 on both sides,

7x +15=120

Subtracting 15 on both sides,

7x=105

Dividing by 7 on both sides,

x=15

Therefore, age of James=15/3=5

Age of Mickel                 =15

Age of John                  =15+5=20

Variable of math problem 2:

Solve the following system:

x + y = 20

2x - y = 10

Sol:

We cay solve x aid y by using substitution method.

Given         x + y = 20……………. (1)

2x - y = 10……………... (2)

Solve the equation (1) for y,

x+ y= 20

Subtract to the value x on both sides,

y= 20-x ………. (3)

Substitute the value y into the second equation. They we get,

2x-(20-x) =10

2x-20+x=10

3x-20= 10

Add to the value 20 on both sides.

3x-20+20= 10+20

3x= 30

Divide by the value 3 on both sides.

x=10

Substitute the value of x into the equation (1).

10+y=20

Add the value -10 on both sides.

y= 20-10

y=10

Answer: x=10 and y=10

Variable of math problem 3:

Solve the equation 7(-5b - 3) - (5b - 4) = -6(4b + 6) + 3

Sol:

Given the equation 7(-5b - 3) - (5b - 4) = -6(4b + 6) + 3

First we can multiple the factor variables for both left and right hand side.

-35b - 21 - 5b + 4 = -24b - 36 +3

Here we can group the like terms on both sides.

-40b - 17 = -24b – 33

Add 20b+15 on both sides.

-40b-17+24b+33=0

-16b+16=0

Subtract 16 on both sides.

-16b= -16

Divide -16 on both sides.

`b= (-16)/-16`

` = 1`

Answer: b=1

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Practice problems of variable in math:


Find x: 5x+3x-6=74
Solve: 3(y -3) + 5z - 4(y -2z -3) + 8
Answer:

x= 10
13z-y+11