Linear Equations

Front 1

Methods to solve the two linear independent equations?

Back 1

1. Multiplication: to multiply two equations by the same number

2. Substitution: to substitute one variable to another equation

Front 2

Interprete linear equation as a graph:

y = a + bx

Back 2

y - the dependent variable which varies with the x value

a - y-intercept which will cut the y axis given x = 0

b - coefficient or slope which refer to how the y value changes when one unit of x changes

x - independent variable which will change the y-value

Front 3

How the linear equation apply to the costing?

y = a + bx

Back 3

In terms of cost:

y = total costs
a = fixed costs which is positive although production units are zero

b = the change in total costs when one unit of x change

x = no. of units produced

Front 4

How to determine the slope of linear equation

Back 4

slope = change in y / change in x (to determine how much y will change for one unit of x change)

Front 5

What is the positive and negative slope mean?

Back 5

Positive slope will go upward as x goes up, y will go up too

Negative slope will go downward as x goes up, y will go down.

Front 6

what is the slope for horizontal line?

Back 6

As x change, y is constant; so slope =
(y2 -y1) / (x2 - x1) = 0 / 1 = 0

Front 7

what is the slope of vertical line?

Back 7

as x is constant, y is changed; so
(y2 -y1) / (x2 - x1) = 1/0 = infinity or the steepest slope.