First observe that if
,

Let
and
. It follows that

Now let
, so
. Solving for
,

which means

Now solve for
.

(note that we assume
)

(we omit
since
is not true)
Answer:

Step-by-step explanation:

proportional relationship in our everyday life: When we put gas in our car, there is a relationship between the number of gallons of fuel that we put in the tank and the amount of money we will have to pay. In other words, the more gas we put in, the more money we'll pay.
28 x 25 = $700
Answer: The class raises at least $700.