The numbers of new CDs is 30 and the old CDs is 21.
To solve this problem, we have to write a system of equations in which we would know the numbers of each types of CD she bought.
<h3>System of Equations</h3>
This is used to solve a series or complex of word problems in which we can represent in a mathematical statements;
- Let n represents numbers of new CDs
- Let u represents numbers of old CDs
The equations can be represented as
Let's take equation (i)
Making n the subject of formula
we can put equation (iii) into equation (ii)
Let's put the value of u into equation (i)
From the calculations above, the numbers of new CDs is 30 and the old CDs is 21.
Learn more on system of equations here;
brainly.com/question/13729904
Answer:
Option C. 
Step-by-step explanation:
we know that
In the right triangle ABC
The tangent of angle B is equal to the opposite side angle B divided by the adjacent side angle B
substitute the values
The equation of the vertical parabola in vertex form is written as
Where (h, k) are the coordinates of the vertex and p is the focal distance.
The directrix of a parabola is a line which every point of the parabola is equally distant to this line and the focus of the parabola. The vertex is located between the focus and the directrix, therefore, the distance between the y-coordinate of the vertex and the directrix represents the focal distance.
Using this value for p and (3, 1) as the vertex, we have our equation
Small triangle: <span>The side // x axis has a length of 4
Large triangle: The side // x axis has a length of 12
So Small/Large = 4/12 = 1/3
Small triangle: <span>The side // y axis has a length of 3
Large triangle: The side // y axis has a length of 9
</span><span>So Small/Large = 3/9 = 1/3
So the scale factor to obtain this dilatation is 1/3</span>
</span>
The solution is negative.
