15 - x = 2(x + 3)
15 - x = 2x + 6
15 = 3x + 6
9 = 3x
3 = x
x = 3
Answer:
The answer is (d) ⇒ eccentricity = 6 , hyperbola , directrix x = 3/2
Step-by-step explanation:
∵ r = ek/(1 ± ecosФ)
∵ r = 9/(1 + 6cosФ)
∴ e = 6 ⇒ eccentricity = 6
∵ e > 1
∴ The conic is hyperbola
∵ ek = 9
∴ k = 9/6 = 3/2
∴ The directrix x = 3/2
Marcia dissolved 1 kg of salt in 3 litres of water
Bobby dissolved 2 pounds of salt in 7 pints of water
We know that
1 litre = 2.11 pints
We also know that
1 pound = 0.4535 kg
Now if we take the case of Bobby, and convert the pound to
kg then
1 pound = 0.4535 kg
2 pounds = (0.4535 * 2) kg
<span> =
0.907 kg</span>
<span>
= 0.91
kg</span>
Bobby dissolved the salt in 7 pints of water
We know
2.11 pints = 1 litre
Then
7 pints = (7/2.11) litre
<span> = 3.32
litres</span>
So we now see that Bobby has dissolved 0.91 kg of salt in
3.32 litres of water
Marcia dissolved 1 kg of salt in 3 litres of water.
So Marcia has made a more concentrated solution since she
has dissolved more salt in less amount of water whereas Bobby has dissolved
less amount of salt in more water.
