Answer:
y = 2x - 1
Step-by-step explanation:
the equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y-intercept )
To find m use the gradient formula
m = ( y₂ - y₁ ) / ( x₂ - x₁ )
with (x₁, y₁ ) = (1, 1) and (x₂, y₂ ) = (5, 9)
m = [tex]\frac{9-1}{5-1}[/tex] = [tex]\frac{8}{4}[/tex] = 2
y = 2x + c ← is the partial equation
To find c substitute either of the 2 points into the partial equation
using (1, 1 ), then
1 = 2 + c ⇒ c = 1 - 2 = - 1
y = 2x - 1 ← equation of line
