Algebra II Homework - Please help!!!

Question

A line through (2,1) has y-intercept b. Express the x-intercept, k, of the line in terms of b.

Answer 1

The line passes through (2, 1) and (0, b)

Start with two-point form.

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

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

-2(y - 1) = (b - 1)(x - 2)

-2y + 2 = bx - 2b - x + 2

x-intercept at y = 0

-2(0) + 2 = bx - 2b - x + 2

-2 = b(x - 2)

-2 / (x - 2) = b