Answer:
3. Since it asked us to write question 3 in the from y=mx + c
m is the gradient
c is the intercept on y axis or where the line enters or cuts the y axis. This can be seen from the diagram. The line cuts the y axis at "9". (Check the diagram for this).
Now to find m.
Pick points on the line
Say (1,6) and (2,3)
Gradient = m = y2 - y1/(X2 - X1)
x1 = 1
y1 =6
x2 = 2
y2 = 3
Substituting into that formula
m = 3 - 6/2 - 1
m= -3/1
m= -3.
Since we've gotten what we need
y=mx + c
Y= -3x + 9.
4. 4x + 2y = 12
Rearranging by making y subject to suit the eqn...y=mx + c
you have
m is the gradient and c is the intercept.
2y = -4x + 12
Divide through by 2
y= -2x + 6
y=mx + c
By comparing...
m==gradient = -2
c== Intercept = 6
5). Doing the same thing we did above
-6x + 3y =21
Making y subject
3y = 6x + 21
Divide through by 3
y= 2x + 7
y=mx + c
m==gradient =2
c==Intercept =7.
Hope this helps.
Have a great day!