Answer:

Step-by-step explanation:
You have what is called "perfect squares" so you can use the "difference of squares formula to factor:

So,

you can work the equation backward now and you will get your original equation.
Answer:
180 fb*lb
45 ft*lb
Step-by-step explanation:
We have that the work is equal to:
W = F * d
but when the force is constant and in this case, it is changing.
therefore it would be:

Where a = 0 and b = 30.
F (x) = 0.4 * x
Therefore, we replace and we would be left with:

We integrate and we have:
W = 0.4 / 2 * x ^ 2
W = 0.2 * (x ^ 2) from 0 to 30, we replace:
W = 0.2 * (30 ^ 2) - 0.2 * (0 ^ 2)
W = 180 ft * lb
Now in the second part it is the same, but the integral would be from 0 to 15.
we replace:
W = 0.2 * (15 ^ 2) - 0.2 * (0 ^ 2)
W = 45 ft * lb
Answer:
B
Step-by-step explanation:
There is no change in cost, so the slope stays the same. since the a dependent variable is cost, it stays on the y axis, and the amount of photocopies is on the x axis. The total amount of money for 8 copies is $1.60, so you would just plug those into the graph and find B to be correct.