Answer:
y = 0.8x - 0.8
Explanation:
Δy ÷ Δx = gradient (x)
4 - -4 = 8
6 - -4 = 10
8 ÷ 10 = 0.8
equation of line; y = mx + c
substitute one of the coordinates into the equation
(6, 4) y = 4, x = 6
4 = 0.8(6) + c
4 = 4.8 + c
- 4.8 to get the y intercept on it's own
-0.8 = y intercept (c)
confirmation
substitute the new values to get the other y
(-4, -4) y = -4 <-- should be the answer, x = -4
y = mx + c
y = 0.8(-4) - 0.8
y = -3.2 - 0.8
y = -4 the gradient and the y intercept have been proven right