Answer:

General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Step-by-step explanation:
<u>Step 1: Define</u>
<u />
<u />
<u />
<u>Step 2: Evaluate</u>
- [Fraction] Exponents:

- [Fraction] Subtract:

- [Fraction] Divide:

A -17 3/4< x so u have to simplify-17 3/4 by multiply 17*4=68+3=71/4 so the x stands for -71/4 and it has to be 4 as the denominator because it it the denominator for the question.
B, C, D are also the same answer-17/4
And for 15 3/4<-2+ x it is also the same answer
Answer:
The numbers:
1, -3, 2, -9, 3, -15, 4, -21,
are not linear.
Step-by-step explanation:
If it was linear:
4, 3, 2, 1, -3, -9, -15, -21
The answer is B. Carlos worked two hours and earned $20
The answer is D, i.e. the system was solved via elimination
If you multiply the first equation by 5, the system becomes

If you sum the two equations, you get

And so if you substitute the second equation of system A with this new equation, you'll get system B.