Answer:
y = 2x + 2
Explanation:
given : line passes through the points (4,10) and (9,20)
Required : write a linear function in terms of x and y
solution :
substitute the coordinate points into the equation: y = mx + b
(x=9, y=20) _ 20 = 9m + b
(x=4, y=10) 10 = 4m + b
subtracting 10 = 5m
m = 10/5
m = 2
substitute x=2 back into eq.1 to solve for b
20 = 9m + b
20 = 9(2) + b
20 - 18 = b
b = 2
therefore the straight line equation is:
y = mx + b
y = 2x + 2