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:
12 students
Step-by-step explanation:
Given
Required
Determine the number of students that eat lunch once a week
In Sets;
If out of 9, at least 7 eats one a week then
9 - 7 eats lunch once a week
<em>In other words;</em>
2 out of 9 students eat lunch once a week
Number of students in this category is then calculated as thus;
Answer:
42 square yards
Step-by-step explanation:
T.S.A of cube
where l = 7yd
thus, the surface area of cube is 42 square yards
Let's solve this system of equations through substitution.
We have these two equations.
-7x-2y=14
6x+6y=18
Now let divide the second equation by 6.
6x+6y=18 ----> x+y=3
Next, let us move y to the right side of the equation.
x+y=3 -------> x=3-y (x equals 3-y)
Because we found out that what x is in terms of y, we can input that in for every instance of x in this equation below.
-7x-2y=14 becomes -7(3-y)-2y=14 (Why? Because x equals 3-y!)
We have a one variable equation now and can solve for y.
-7(3-y)-2y=14
-21+7y-2y=14
5y=35
y=7
Plug in 7 for y in any equation to find x.
x+y=3
x+7=3
x=-4
answer: x=-4, y=7
Answer:
There's 10
Step-by-step explanation:
You count the little squares, which give you 9 and then you count the big square that all of the little squares are in, which gives you 10 squares in total
