Answer:
(3, 2)
General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
<u>Algebra I</u>
- Solving systems of equations using substitution/elimination
Step-by-step explanation:
<u>Step 1: Define Systems</u>
y = 2x - 4
y = -x + 5
<u>Step 2: Solve for </u><em><u>x</u></em>
<em>Substitution</em>
- Substitute in <em>y</em>: 2x - 4 = -x + 5
- Add <em>x</em> to both sides: 3x - 4 = 5
- Add 4 to both sides: 3x = 9
- Isolate <em>x</em>: x = 3
<u>Step 3: Solve for </u><em><u>y</u></em>
- Define equation: y = -x + 5
- Substitute in <em>x</em>: y = -3 + 5
- Add: y = 2
The correct expression that is equivalent to the algebraic expression -5x - 15 + 25x - 30 is -5(-4x + 9).
<h3>How to determine the equivalent expression</h3>
We shall simplify the given algebraic expression by carrying out basic mathematics operations as follows;
Given: -5x - 15 + 25x - 30
we group like terms together
25x - 5x - 15 - 30
20x - 45
the number 5 is a common factor of 20x and 45, so we have that;
5 × 4x - 5 × 9
by factoring out 5
5(4x - 9)
also;
5(4x - 9) = -5(-4x + 9)
Therefore, -5(-4x + 9) is an equivalent expression to the algebraic expression -5x - 15 + 25x - 30
Learn more about equivalent expression here: brainly.com/question/24734894
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If there is more to the answer than what I give please ask for more!
With

we can find

by substituting 4 into the main function.
So it would look like this:

Hope this helps!
Answer:
11) 67%; 12) 25%
Step-by-step explanation:
Problem 11: Find the fraction representing 30 out of a total of 45, and then multiply the result by 100%:
30/45 = 2/3 = 0.67; then we see that 30 is 67% of 45.
Problem 12: Same method:
16/64 = 1/4 = 0.25. Mult. this by 100%: 16 is 25% of 64.