Given:
The area model for
.
To find:
The value of
and the missing values in the area model.
Solution:
2.1 can be written as 2 and 0.1 on the left side of the area model.
3.2 can be written as 3 and 0.2 on the top of area model.
Area of the four parts of the area model are:




The complete area model is shown below.
After adding all areas of the area model, we get

Therefore, the value of
is 6.72 and the missing values of the area model are 0.3 and 0.02 respectively.
Y=-6-x is not equal to 2x+y=12. Both sides were not divided by two when it was simplified.
Most textbooks interpret standard form of a quadratic function to be as follows:
f(x) =

In the function f(x) =

, notice we do not have a value for "c". Just place a "0" in for the c and you have standard form.
the criteria for standard form:
1. All like terms are combined
2. Degree must drop from left to right
3. The leading coefficient cannot be equal to zero.