Answer:
1. y = - 4 x + 5
2. x = -8
Step-by-step explanation:
1. (-1,9) (1,1)
y = mx + b
m = (y-y') / (x-x') = (1-9) / (1-(-1)) = -8 / 2 = - 4
b = y - mx = 9 - (-4) x (-1) = 5
equation: y = - 4 x + 5
check: (1,1) y=1 = (-4) x 1 + 5 = 1
2. Vertical line through (-8,6) is a line perpendicular to x axis
x = -8
Answer:
C
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 calculate m use the gradient formula
m = ( y₂ - y₁ ) / ( x₂ - x₁ )
with (x₁, y₁ ) = (0, - 2) and (x₂, y₂ ) = (4, - 1) ← 2 points on the line
m = =
note that the line crosses the y-axis at (0, - 2) ⇒ c = - 2
y = x - 2 ← equation of line
