Question

Which is not an equation of the line going through (3.-6) and (1, 2)?

O A. y+6=-4(x-3)
O B. y-1 =-4(x - 2)
O C. y-2=-4(x-1)
O D. y=-4x+6

Answer 1

B

Explanation:

The equation of a line in point- slope form is

y - b = m(x - a)

where m is the slope and (a, b) a point on the line

Calculate m using the slope formula

m = (y₂ - y₁ ) / (x₂ - x₁ )

with (x₁, y₁ ) = (3, - 6) and (x₂, y₂ ) = (1, 2)

m =
`(2+6)/(1-3)` =
`(8)/(-2)` = - 4

Using m = - 4 and (a, b) = (3, - 6), then

y - (- 6) = - 4(x - 3), that is

y + 6 = - 4(x - 3) → equation A on list

Using m = - 4 and (a, b) = (1, 2), then

y - 2 = - 4(x - 1) → equation C on list

Distribute and simplify

y - 2 = - 4x + 4 ( add 2 to both sides )

y = - 4x + 6 → equation D on list

The above are 3 valid equations of the line

Thus B is not the equation of the line.