We are asked to expand and simplify the expression $(y+3)(y-4)(2y-1)$. We are also asked to make $x$ the subject of the formula $x = \frac{3+x}{y}$.

1. Problem Description

We are asked to expand and simplify the expression $(y+3)(y-4)(2y-1)$.

We are also asked to make $x$ the subject of the formula $x = \frac{3+x}{y}$.

2. Solution Steps

(c) Expanding and simplifying $(y+3)(y-4)(2y-1)$:

First, we expand $(y+3)(y-4)$:

$(y+3)(y-4) = y(y-4) + 3(y-4) = y^2 - 4y + 3y - 12 = y^2 - y - 12$

Next, we multiply the result by $(2y-1)$:

$(y^2 - y - 12)(2y-1) = y^2(2y-1) - y(2y-1) - 12(2y-1)$

$= 2y^3 - y^2 - 2y^2 + y - 24y + 12$

$= 2y^3 - 3y^2 - 23y + 12$

(d) Making $x$ the subject of the formula $x = \frac{3+x}{y}$:

Multiply both sides by $y$:

$xy = 3 + x$

Subtract $x$ from both sides:

$xy - x = 3$

Factor out $x$:

$x(y-1) = 3$

Divide both sides by $(y-1)$:

$x = \frac{3}{y-1}$

3. Final Answer

(c) The expanded and simplified expression is $2y^3 - 3y^2 - 23y + 12$.

(d) $x$ as the subject of the formula is $x = \frac{3}{y-1}$.