If (x+k) is a favor of f(x) which of the following must be true? a) f(k)=0 b) f(-k)=0 c) a root of f(x) is x=k d) a y-intercept of f(x) is x=-k

B

Step-by-step explanation:

A factor of f(x) has the form (x+k). We know to find the zeros or roots of the function we set the factors equal to 0.

So (x+k)=0 and solve for x. x=-k. This means f(-k)=0.

The second option is the better buy

The option where a 32 pack cost $49.60

Explanation:

Since we have different counts (30 vs 32) we can't directly compare the cost. If both had 32 rolls each, then we could easily see that the first option is cheaper. But unfortunately both counts aren't the same.

However, we can find the cost per single roll and compare those unit costs. The term "unit" means "one". So "unit cost" means "cost per 1 item".

To find the unit cost or unit price, we will divide the given cost over the given count. Consider the example where 5 rolls cost 12 dollars. We can then set up the equation like so

5 rolls = 12 dollars

Then divide both sides by 5 to turn the "5 rolls" into "1 roll"

5/5 rolls = 12/5 dollars

1 rolls = 2.40 dollars

The unit cost is 2.40 dollars per roll, ie, each roll costs $2.40

So this is why we divide in this order.

For the first option we have a unit cost of 48.36/30 = 1.612 = 1.61 dollars per roll.

For the second option, we have a unit cost of 49.60/32 = 1.55 dollars per roll.

The second option provides the cheaper unit price, even though it appears to be the more expensive option. So the second option is the better buy.