Answer:
Step-by-step explanation:
The y intercept, also known as 'c' in the formula y = mx + c acts as the coordinate for y when x = 0 [E.g. (0, 24) which c = 24]
Question 1 = y = -5x + 50
On the graph, c = 50 [ y = mx + 50 ]
30 - 15 = 15
7 - 4 = 3
15/3 = 5 (for the gradient, or 'm', which you may use the formula 'rise/run' on the line shown) [ y = 5x + 50 ]
ALTHOUGH, in question one, the line has a Negative Correlation, it slants downwards on the slope, so the gradient will be negative : y = -5x + 50
If x = 9, y = (9 x -5) + 50, = -5
y = -5
Question 2 = y = 2.5x + 5
c = 5
m = 5/2 = 2.5
y = 2.5x + 5
when y = 30 > x = 10
30 = 2.5x + 5
30 - 5 = 25
25 = 2.5x
x = 25/2.5
x = 10
Question 3 = y = -10x + 50
c = 50
m = (30 - 20) / 1 = 10
y = -10x + 50
when x = 4 > y = (-10 x 4) + 50
y = -40 + 50
y = 10
