The value of b : 3
Further explanation
Given
slope=m=1.5
points (0,3) and (4,9)
Required
The value of b
Solution
the Equation of a Line : y = mx + b
m = slope
b = constant
Find the slope :
m = (y₂-y₁)/(x₂-x₁)
m = (9-3)/(4-0)
m = 6/4
For the point that the line passes through : (0,3) then the equation :
3=6/4.0+b
3=b
And the equation :
y = 6/4x+3