Question

Work out m and c for the line: 3 y + 6 x = − 3

Answer 1

m is -2 and c is -1

Explanation:

• Let's first phrase out the general equation of a line

`{ \rm{y = mx + c}}`

• m is the slope
• c is the y-intercept

[ remember that a general line equation must be in slope - intercept form as shown above ]

• from our question, we are given the equation;

`{ \rm{3y + 6x = - 3}}`

• let's make y the subject in order to make the equation in slope - intercept format.

→ remember to apply "subject making knowledge"

`{ \rm{3y = - 3 - 6x}} \\ \\ { \rm{3y = - 6x - 3}} \\ \\ { \rm{ (3y)/(3) = ( - 6x)/(3) - (3)/(3) }} \\ \\ { \boxed{ \rm{y = - 2x - 1}}}`

• The above boxed equation is now a general equation. Let's extract out slope, m and y-intercept, c

`{ \rm{m \: \dashrightarrow \: - 2}} \\ \\ { \rm{c \: \dashrightarrow \: - 1}}`