It has become somewhat fashionable to have students derive the Quadratic Formula themselves; this is done by completing the square for the generic quadratic equation ax2 + bx + c = 0. While I can understand the impulse (showing students how the Formula was invented, and thereby providing a concrete example of the usefulness of abstract symbolic manipulation), the computations involved are often a bit beyond the average student at this point.
Diameter- Is two times the radius. Circumference is the distance around the edge of the circle.
Radius- A line from the center of a circle to a point on the circle.
Hope this helped.
Answer:
20.65%
Step-by-step explanation:

Answer:
see explanation
Step-by-step explanation:
Given
2x² + 7x = 15 ( subtract 15 from both sides )
2x² + 7x - 15 = 0 ← in standard form
To factorise the left side
Consider the factors of the product of the coefficient of the x² term and the constant term which sum to give the coefficient of the x- term
product = 2 × - 15 = - 30 and sum = + 7
The factors are + 10 and - 3
Use these factors to split the x- term
2x² + 10x - 3x - 15 ( factor the first/second and third/fourth terms )
2x(x + 5) - 3(x + 5) ← factor out (x + 5) from each term
(x + 5)(2x - 3) ← in factored form
Answer:
Step-by-step explanation:
Let us assume that if possible in the group of 101, each had a different number of friends. Then the no of friends 101 persons have 0,1,2,....100 only since number of friends are integers and non negative.
Say P has 100 friends then P has all other persons as friends. In this case, there cannot be any one who has 0 friend. So a contradiction. Hence proved
Part ii: EVen if instead of 101, say n people are there same proof follows as
if different number of friends then they would be 0,1,2...n-1
If one person has n-1 friends then there cannot be any one who does not have any friend.
Thus same proof follows.