The ball will hit the ground at 2 seconds.
Step-by-step explanation:
Given that,
The path of the ball = h(x)=−2x2+1x+6
Here,
x is the time while h is the height of ball.
When the ball will hit the ground, the height will become zero. Therefore,
h(x)=−2x2+1x+6
0 =−2x2+1x+6
or
2x2 -1x - 6 = 0
This is a quadratic equation, hence by applying quadratic equation formula:

here,
a = 2
b = -1
c = -6
Putting these values in formula, we get




x = 2, -3/2
As the time cannot be negative. Therefore, the ball will hit the ground at 2 seconds.
Given:
Amount = 8700
Time = 3 years
Rate of interest = 24% per annum
To find:
The principal values.
Solution:
Formula for amount:

Where, A is amount, P is principal, r is the rate of interest and t is the number of years.
Putting
, we get




Divide both sides by 1.906624.



Therefore, the principal value is about 4563.04.
Answer:
The son is 20
The man is 60
Step-by-step explanation:
We can set up this equation with what we know. Let <em>m</em> stand for the Man's current age, and let <em>s</em> stand for his son's current age.
We know the Man's current age is three times that of his son, so this equation can be written as: <em>m = 3s</em>
Ten years ago means the man's current age <em>minus</em> 10 years. So it is <em>m-10</em>. So ten years ago he was 5 times his son's age 10 years ago, <em>5(s-10)</em>
This can be written as: <em>m-10=5(s-10)</em>
Solve with either substitution or elimination, the choice is yours, it doesn't really matter which method you use. I'll be using substitution.
<em>m-10=5(s-10)</em>
<em>3s-10= 5s-50</em>
<em>40=2s</em>
<em>20 = s</em>
The son is <em>20</em> years old.
We know the man is currently 3 times his son's age, because <em>m=3s</em>, so just solve for m since you now know the value of <em>s.</em>
<em>m=3s</em>
<em>m=3(20)</em>
<em>m=60</em>
The man is <em>60</em> years old
A positive
as there are 4 negetive multiplied