3m^2+2p^2-15
3(3)^2+2(10)^2-15
3(9)+2(100)-15
21+200-15
206
Answer:
(a) 
(b) Domain:
<em>(See attachment for graph)</em>
(c) 
Step-by-step explanation:
Given



Solving (a): A function; l in terms of w
All we need to do is make l the subject in 
Divide through by 2

Subtract w from both sides


Reorder

Solving (b): The graph
In (a), we have:

Since l and w are the dimensions of the fence, they can't be less than 1
So, the domain of the function can be 
--------------------------------------------------------------------------------------------------
To check this
When 



When 


--------------------------------------------------------------------------------------------------
<em>See attachment for graph</em>
<em></em>
Solving (c): Write l as a function 
In (a), we have:

Writing l as a function, we have:

Substitute
for l in 
becomes

Answer:
x = 7
Step-by-step explanation:
Hi,
7x - 7 = 4x + 14
3x - 7 = 14
3x = 21
x = 7
I hope this helps :)
I think the answer to (Y) may be 40 cubic units