Answer:
30
Step-by-step explanation:
12 is 40% of the total number of cards.
12 = 0.4x, where x is total number of cards
/0.4 /0.4
30 = x
30 cards
Complete the square in the denominator.

Rewrite the given transform as

Now take the inverse transform:

Step-by-step explanation:
the rhombus is both rectangle and square
The solutions for
is option 3. 
Step-by-step explanation:
Step 1:
First, we must bring the equation to the form of 
So
becomes 
The value of a is the coefficient of the
term, the value of b is the coefficient of x term and c is the coefficient of the constant term.
Comparing the above equation to
we get
and 
We have the formula 
Step 2:
By substituting the known values, we get


This is the third option.
It only falls inside the trapezoid bc the circle goes through the point (0,2) so it isnt on 1.5