P = L + L + w + w
72 = 2(L) + 2(L-4)
Distribute
72 = 2(L) + 2(L) - 8
Add like terms
72 = 4(L) - 8
Subtract 8 from both sides
64 = 4(L)
Divide both sides by 4
16 = L
The length is 16. Now substitute that in the equation for finding w.
w = L - 4
w =
Are the directions asking you to solve these ?
Let m and j be the current ages of Matthew and Jenny, respectively.
Now, Matthew is 3 times as old as Jenny, so the variables are in the following relation:

In 7 years, both of them will be 7 years older, i.e. their ages will be m+7 and j+7, and Matthew will be twice as old:

Now, remembering that m=3j, we can rewrite the second equation as

So, Jenny is 7 and Matthew is 21 (he's 3 times older).
In fact, in 7 years, they will be 14 and 28, and Matthew will be twice as old.
Answer:
Sample response:
Step-by-step explanation:
She would multiply the rate by the years to find the average rise in water levels, or 1.8 times 6.2 = 11.16. To find the difference between the water levels, she would subtract -13.64 from 11.16.
parallel means "same slope (m)"
m =
= 
Now, input the point (0, 0) and the slope
into the Point-Slope formula:
y - y₁ = m(x - x₁)
y - 0 =
(x - 0)
y = 
3y = -5x <em>multiplied both sides by 3</em>
0 = -5x - 3y <em>subtracted 3y from both sides</em>
Answer: C