Answer:
<em>(a) x=2, y=-1</em>
<em>(b) x=2, y=2</em>
<em>(c)</em> 
<em>(d) x=-2, y=-7</em>
Step-by-step explanation:
<u>Cramer's Rule</u>
It's a predetermined sequence of steps to solve a system of equations. It's a preferred technique to be implemented in automatic digital solutions because it's easy to structure and generalize.
It uses the concept of determinants, as explained below. Suppose we have a 2x2 system of equations like:

We call the determinant of the system

We also define:

And

The solution for x and y is


(a) The system to solve is

Calculating:





The solution is x=2, y=-1
(b) The system to solve is

Calculating:





The solution is x=2, y=2
(c) The system to solve is

Calculating:





The solution is

(d) The system to solve is

Calculating:





The solution is x=-2, y=-7
Answer:
0.0656
Step-by-step explanation:
For each message, we have these following probabilities:
90% probability it is spam.
10% probability it is legitimate.
Compute the probability that the first legitimate e-mail she finds is the fifth message she checks:
The first four all spam, each with a 90% probability.
The fifth legitimate, with a 10% probability.

Answer:
choice #3) similar by SSS
The corresponding sides do have the correct ratios.
1,000,000 is the answer (it would be rounded up since its a 6 in the ten thousands place)
Answer:
She will need to work 13 weeks at her job in order to pay for her TV