Correct Answer: - 550
We can use the distributive property to distribute the summation to the variables and then get the constant out to apply the summation formulas as shown below in the attached image.
The equation editor does not have a summation symbol, so I have attached the solution using the image.
The correct answer to this question is -550. First option is the correct one.
I like the substitution method. Which is when you make one equation equal only x or y and plug it into the other equation)
There is also the graphing method. If you graphed it, it might not be quite as accurate (at least on hand, on computer you would be pretty exact)
Then there is the elimination method. You multiply one of the equations by a coefficient so that you can eliminate x or y from the equation.
Using an ordered pair is a way of graphing a linear equation on a coordinate plane.
{(-1, 2), (0, 1), (1, 2), (4, 5)}.
Answer:
x = -2
y = -1
(-2, -1)
General Formulas and Concepts:
<u>Pre-Algebra</u>
- Order of Operations: BPEMDAS
- Equality Properties
<u>Algebra I</u>
- Solving systems of equations using substitution/elimination
- Solving systems of equations by graphing
Step-by-step explanation:
<u>Step 1: Define systems</u>
y = x + 1
3x + 3y = -9
<u>Step 2: Solve for </u><em><u>x</u></em>
<em>Substitution</em>
- Substitute in <em>y</em>: 3x + 3(x + 1) = -9
- Distribute 3: 3x + 3x + 3 = -9
- Combine like terms: 6x + 3 = -9
- Isolate <em>x</em> term: 6x = -12
- Isolate <em>x</em>: x = -2
<u>Step 3: Solve for </u><em><u>y</u></em>
- Define original equation: y = x + 1
- Substitute in <em>x</em>: y = -2 + 1
- Add: y = -1
<u>Step 4: Graph systems</u>
<em>Check the solution set.</em>