Answer:The answer is 3 & 7
Step-by-step explanation:3 x 7 = 21
3 + (7) = 10
Are you asking because you are trying to figure out how to factor the following quadratic equation?
x2 + 10x + 21 = 0
If so, the solution to factor the quadratic equation above is:
(X + 3 ) (X + 7)
To summarize, since 3 and 7 multiply to 21 and add up 10, you know that the following is true:
x2 + 10x + 21 = (X + 3 ) (X + 7)
You're standing there at the edge of the answer but you're afraid to jump in. Take a long hard look inside the parentheses. Stare at it and don't blink.
Isn't 4n^2. a square ? Isn't. 9. a square ? Is that so ! Then isn't (4n^2 - 9) the difference of squares ! ? ! Go ahead. Take the plunge.
B. If (x = 5)
Hope this helped :)
Answer:
about 5.613 seconds
Step-by-step explanation:
Using the quadratic formula to find the value of t when h = 0, we have ...
at² +bt +c = 0
t = (-b±√(b²-4ac))/(2a)
t = (-72±√(72² -4(-16)(100)))/(2(-16))
t = (-72±√11584)/-32 = (9±√181)/4
Only the positive value of t is of interest.
The coin will hit the stream after (9+√181)/4 seconds ≈ 5.613 seconds.
