Because this is a fourth degree that will be tricky to factor as it is, we will do a u substitution. Let . We can now rewrite that polynomial in terms of u:
. Filling into the quadratic formula we have
. Simplifying down
and
or
. That means that u = 8 or u = -1. But don't forget that we let
, so we have to put x-squared back in for u. That gives us
which simplifies down to
. That also gives us
. When we take the square root of -1, we have to use the fact that -1 = i^2, so we sub that in to get
. All in all, your solutions are as follows:
which is choice b.
What is 222222+78887797
2 answers:
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so solve for "x", to see how much is the company paying for the purchase of 1 minute
now, they're plan to sell the minute for 8cents, how much is the profit?
that is, the difference from their cost of the cents to the planned selling price.
bear in mind, is 46,000,000 minutes, so whatever value you get for 1minute,
you need to multiply it for 46,000,000 to get the actual cost.
and the revenue from the sell of 8cents per minute, is of course, 8 * 46,000,000
profit = revenue - cost