Answer:
y = 
Step-by-step explanation:
Given that y varies directly as x then the equation relating them is
y = kx ← k is the constant of variation
To find k use the condition y = 7 when x = 3
k =
=
, thus
y =
x ← equation of variation
When x = 7, then
y =
× 7 = 
Answer:
14, 15
Step-by-step explanation:
We have this equation:

So, we need to solve this equation for L. Then we sum -2W in each member of the equation, like this:


Then, dividing the equation by 2:

Finally, let's order this equation:
Answer:
26
Step-by-step explanation: