Answer
(a) $y = 2x + b$
(b) $y = mx + 1 - 2m$
(c) $y = 2x-3$
The graph sketches are shown in the following image:
Work Step by Step
(a) A linear equation has the form $y = mx + b$. Thus, the family of linear equations with slope 2 would have the form $y = 2x + b$. The sketches show arbitrary values of b for said equation.
(b) A linear equation can also have the form $y-y_1 = m(x-x_1)$. Thus, the family of linear equations such that $f(2) = 1$ would have the form:
$y-1 = m(x-2)$
$y-1 = mx - 2m$
$y = mx + 1 - 2m$
The sketches show arbitrary values of m for said equation.
(c) Input $m=2$, the characteristic of the family of linear equations in (a), to the equation in (b) to find the equation that belongs to both families. This results in:
$y = 2x + 1 - 4$
$y = 2x -3$