Let numbers of books be 'b' and numbers of CDs be 'c'
We can set up two equations:
Equation [1] ⇒

Equation [2] ⇒

We are solving for the number of books and the number of CDs bought
When we have two equations in terms of two different variables;

and

, that we need to solve, then this becomes a simultaneous equation problem.
First, rearrange Equation [1] to make either

or

the subject:


Then we substitute

into Equation [2]






Now we know the value of

which is

, substitute this value into

we have

Answer:
Numbers of books = 13
Numbers of CDs = 7
An imaginary number is a complex number that can be written as a real number multiplied by the imaginary unit i, which is defined by it's property i² = −1. The square of an imaginary number bi is −b². For example, 5i is an imaginary number, and it's square is −25.
Answer:
Cost of 18 pounds candy = $22.5
Cost of 10 pounds candy = $12.5
Cost of 1 pound of candies = $1.25
Step-by-step explanation:
6 pounds of butterscotch candies cost $7.50
⇔ 1 pound of same candy costs
$1.25
Now, we need to find the cost of 18 pounds of candy:
as, the cost of 6 pounds candy = $7.50
⇔ Cost of 6 x 3 = 18 pounds candy = $7.50 x 3 = $22.5
Cost of 10 pounds candy = 10 x (Cost of 1 pound candy)
= 10 x ($1.25) = $12.5
The unit rate for butterscotch candies = Cost of 1 pound of candies
= $1.25
Answer:
8/21
Step-by-step explanation:
2/7 ÷ 3/4
2/7 * 4/3
8/21