Question

2x + 5y = 15 8x + 4y = 8​

Answer 1

(-5/8, 13/4)

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

1. Brackets
2. Parenthesis
3. Exponents
4. Multiplication
5. Division
6. Addition
7. Subtraction

• Left to Right

Equality Properties

Algebra I

• Solving systems of equations using substitution/elimination
• Solving systems of equations by graphing

Explanation:

Step 1: Define systems

2x + 5y = 15

8x + 4y = 8

Step 2: Rewrite systems

8x + 4y = 8

1. Subtract 8x on both sides: 4y = 8 - 8x
2. Divide 4 on both sides: y = 2 - 2x

Step 3: Redefine systems

2x + 5y = 15

y = 2 - 2x

Step 4: Solve for x

Substitution

1. Substitute in y: 2x + 5(2 - 2x) = 15
2. Distribute 5: 2x + 10 - 10x = 15
3. Combine like terms: -8x + 10 = 15
4. Isolate x term: -8x = 5
5. Isolate x: x = -5/8

Step 5: Solve for y

1. Define original equation: 2x + 5y = 15
2. Substitute in x: 2(-5/8) + 5y = 15
3. Multiply: -10/8 + 5y = 15
4. Simplify: -5/4 + 5y = 15
5. Isolate y term: 5y = 65/4
6. Isolate y: y = 13/4

Step 6: Graph systems

Check the solution set.

The solution set is equivalent (is in decimal form).