Question

Write an equation of the line that passes through the points (-1, 3) and (2, -3).

y = -2x + 1

y = -2x + 5

y = (-½)x + (5/2)

y = (-½)x + (½)

Answer 1

Hello from MrBillDoesMath!

Answer:

y = -2x + 1

Discussion:

Let m = slope of line. Then

m = (change in y ) / (change in x)

= (-3 - 3)/(2- -1)

= -6/ (2 +1)

= -6/3

= -2

So y = mx + b = -2x + b. As the line passes through the point (2, -3), by substitution,

-3 =-2(2) + b => as 4 to both sides

-3 + 4 = ( -2(2) +4) + b => (-2(2) +4) = -4 + 4 = 0

1 = 0 + b =>

b = 1

The equation of the line is y = -2x + 1, the first choice provided

Thank you,

MrB