Equation of Straight Line
.
1
Determine the equation of the line that goes through points (–2, –1) and (5, 20)
3 Marks
Show Answer
y = 7x – 3
2
Determine the equation of the line that goes through points (–5, –38) and (2, 11)
3 Marks
Show Answer
y = 3x + 15
3
A botantist records the heights of different plants.
The scattergraph shows the relationship between age (A days) and the height (H mm).
A line of best fit is shown,
Point K represents a plant 2 days old with height of 72mm.
Point G represents a plant 14 days old with height of 432 mm
a Find the equation of the lines of best fit in terms of A and H.
Give your equation in its simplest form
3 Marks
Show Answer
H = 30A + 12
b Use your equation to estimate the height of plant that is 5 days old
3 Marks
Show Answer
H = 162mm
4
A straight line has equation 5x + 3y = 15
a Determine the gradient of the line
2 Marks
Show Answer
m = -5/3
b Find the coordinates of the point where this crosses the x axis
2 Marks
Show Answer
(3, 0)
5
Determine the equation of the line that goes through points (–3, –14) and (7, 16)
3 Marks
Show Answer
y = 3x – 5
6
Determine the equation of the line that goes through points (–8, –14) and (24, 2)
3 Marks
Show Answer
y = ½x – 10
7
Determine the equation of the line that goes through points (–4, 14) and (6, –16)
3 Marks
Show Answer
y = –3x + 2
8
The graph below shows the relationship between the production and costs of a company
Point A represents production of 5 units and a cost of £200.
Point A represents production of 25 units and a cost of £800.
a Find the equation of the lines of best fit in terms of P and C.
Give your equation in its simplest form
3 Marks
Show Answer
C = 30P + 50
9
The graph below shows a straight line connecting points P and Q
Determine the equation of line PQ
Give your equation in its simplest form
3 Marks
Show Answer
y = 5x – 7