Question

What is the equation of the graph above?

A. y+x =-3
B. y= -3x +1
C. y= 3x +1
D. y= -3x -1

Answer 1

B. y = -3x + 1

Explanation:

• A(1,-2) → (x1, y1)
• B(0,1) → (x2, y2)

straight line equation?

Answer:

y-y1 / y2 - y1 = x - x1 / x2 - x1

y - (-2) / 1 - (-2) = (x - 1) / (0 - 1)

(y + 2) / (1 + 2) = ( x - 1) / -1

(y + 2) / 3 = (x - 1) / - 1

-1(y + 2) = 3(x - 1)

-y - 2 = 3x - 3

-y = 3x - 3 + 2

-y = 3x - 1

__________ × (-)

y = -3x + 1