Answer:
A computer is an electronic device for storing and processing data, typically in binary form, according to instructions given to it in a variable program.
<span>200 < 225 + 80x < 550
The 200 is the amount the Jenna currently have.
225 + 80x is the amount that Jenna has to pay given x number of hours.
550 is the sum of Jenna's 200 and additional 350 she can get by selling pre-ordered Cds. This is the maximum amount she can pay for the studio rental and sound technicians.
225 + 80x < 550
80x < 550 -225
80x < 325
80x / 80 < 325/80
x < 4.06 or 4 hours
225 + 80x </span>→ 225 + 80(4) = 225 + 320 = 545
<span>
The number of hours for the sound technician will range from 1 hour to 4 hours.
Assuming they will use 6 hours.
225 + 80(6) = 225 + 480 = 705
705 - 550 = 155
Jenna has to raise an additional $155 to pay off the studio rent and 6 hours of sound technicians.
</span>
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
check the picture below.
notice, a function that is decreasing, namely have a negative slope, doesn't have to be negative.