Answer:
-10,10
Step-by-step explanation:
The given quadratic equation is

The discriminant of this equation is given by;

where a=k, b=20, c=k
For rational solutions, the discriminant must be zero.

Simplify to get:

This implies that:


Take square root to get:



Answer: the old price for 1 liter is $0.3
Step-by-step explanation:
Let x represent the old price for 1 liter of petrol.
Last week a man bought 20 liters at the old price. This means that the total amount that the man paid for 20 liters is 20x.
The cost of petrol rises by 2 cents a liter. This means that the new price per liter is x + 2/100 = x + 0.02
This week he bought 10 liters at the new price. This means that the total amount that the man paid for 10 liters is
10(x + 0.02)
= 10x + 0.2
Altogether, the petrol costs $9.20. This means that
20x + 10x + 0.2 = 9.2
30x + 0.2 = 9.2
30x = 9.2 - 0.2
30x = 9
x = 9/30
x = 0.3
2x + y = 10 is y = -2x + 10
4x + 7 = 40
-7 -7
4x = 33
4 4
x = 8.25
y = -2(8.25) + 10
y = -6.5 and x = 8.25
Hope this helps :)
<h3>
Answer: B) hyperbola</h3>
If the cutting plane was parallel to the circular base of the cones, then we would have a circular cross section (assuming the plane doesnt cut through the vertex). However, we're told than the plane intersects both nappes, or cones, so it's not possible for the plane to be parallel to the base faces. We can rule out choice A.
We can rule out choice C and choice D for similar reasons. An ellipse only forms if the plane only cuts through one cone only, which is the same story for a parabola as well.
Answer:
What is the question?
Step-by-step explanation: