Explanation:
Conversion of a quadratic equation from standard form to vertex form is done by completing the square method.
Assume the quadratic equation to be
where x is the variable.
Completing the square method is as follows:
- send the constant term to other side of equal

- divide the whole equation be coefficient of
, this will give 
- add
to both side of equality 
- Make one fraction on the right side and compress the expression on the left side

- rearrange the terms will give the vertex form of standard quadratic equation

Follow the above procedure will give the vertex form.
(NOTE : you must know that
. Use this equation in transforming the equation from step 3 to step 4)
Answer:
81
Step-by-step explanation:
trust me its correct
5 can stay as is, but 5503 can be rounded to 5500 so 5500x5=27500
Answer:
Step-by-step explanation:
We can solve this question using proportion
Perimeter of the square/Time is takes to unlock
We are told in the question that:
The cellphone unlocks when the perimeter reaches 32 centimeters, taking a total of 2.5 seconds.
Hence, the perimeter of the square after 1.5 seconds is:.x = unknown
32/2.5 = x/1.5
Cross Multiply
2.5x = 32 × 1.5
x = 32 × 1.5/2.5
x = 19.2 centimeters