Answer:
=468 m^2
Step-by-step explanation:
Surface area of a prism is
SA = 2 (lw + wh + hl) where l is length, w is width and h is height
SA = 2 ( 12*6 + 6*9 + 9*12)
= 2 ( 72+54+108)
= 2(234)
=468 m^2
Answer:
B The cost to use the service for one month if zero songs are downloaded
Question:
Find the constant of proportionality k. Then write an equation for the relationship between x and y

Answer:
(a) 
(b) 
Step-by-step explanation:
Given

Solving (a): The constant of proportionality:
Pick any two corresponding x and y values


The constant of proportionality k is:




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

k can also be expressed as:

Substitute values for x1, y1 and k

Cross multiply:

Open bracket

Add 10 to both sides


<em><u>Answer 1: 177 – 77 = 100 </u></em>
<em><u>Answer 2: (7+7) * (7 + (1/7)) = 100</u></em>
The only error you made is on problem 3. Everything else is correct. Nice work.
-------------------------------------------------------
Here is how to solve problem 3
Plug x = 1 into the equation and solve for y
-3x + y = 1
-3*1 + y = 1 ... replace x with 1
-3 + y = 1
y - 3 = 1
y - 3 + 3 = 1 + 3 .... add 3 to both sides
y = 4
<h3>The answer is 4</h3>
-------------------------------------------------------
Verifying the answer:
Plug (x,y) = (1,4) into the equation. Both sides should be the same number after simplifying both sides.
-3x + y = 1
-3*1 + 4 = 1 ..... replace x with 1; replace y with 4
-3 + 4 = 1
1 = 1
The answer is confirmed.
If you were to graph -3x + y = 1, which is equivalent to y = 3x+1, you'll find that the point (1,4) is on this line.