Question 93648
Question:

Find an example from your line of work or daily life that can be expressed as a linear equation with two variables. Graph this equation.


Answer:

Example.

Ann's father's age is 7 years more than 3 times Ann's age. Express this statement an a linear equation and also graph the equation.


Solution: 

Suppose Ann's age = x years.


Suppose Ann's father's age = y years.


Three times Ann's age = 3x


7 years more than  3 times Ann's age = 3x + 7


Then we can write,  y = 3x + 7, which is a linear equation in two variables.


To graph the equation, put some arbitrary values for x and then find out the corresponding values of y as follows.


When, x = 1, y = 3*1 + 7 = 10



When, x = 0, y = 3*0 + 7 = 7



When, x = 2, y = 3*2 + 7 = 13



When, x = -1, y = 3*-1 + 7 = 4



and so on.


Now plot these points on a graph paper.



Then the graph will come likes this....



{{{ graph( 500, 500, -9, 9, -10, 10, 3x + 7 ) }}} 


Hope you found the explanation useful.



Regards.



Praseena.