
Thickness of the book is ~
Refer to the attachment for solution ~
Y = -2x + b
Plug in the point
7 = -2(-1) + b
7 = 2 + b
b = 5
Final equation y = -2x + 5
Given parameters:
y varies directly as w;
This interpreted implies that as y increases, we increases by a certain factor or amount;
So, y ∝ w
y = kw
where k is the constant of proportionality
Now, given that y = 8 and w = 2
Input in the equation to solve for k;
8 = k x 2
Solving k gives, k = 4
Now to the second part,
if v is directly proportional to w;
v = k w
So v = 4w
The equation that relates v to w is v = 4w
Answer:
8 I belive is C and 9 I think is D :)