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Solve each system of eaquasions x+4y=4 -x+2y=8​

2 Answers

13 votes
x + 4y = 4
-x + 2y = 8


x + 4y - x + 2y = 4 + 8

6y = 12

y = 2


x + 4(2) = 4
x + 8 = 4
x = -4

(x,y)
(-4,2)
User UnknownStack
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5.3k points
3 votes

Answer:

(-4, 2)

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

Distributive Property

Equality Properties

  • Multiplication Property of Equality
  • Division Property of Equality
  • Addition Property of Equality
  • Subtraction Property of Equality

Algebra I

  • Terms/Coefficients
  • Coordinates (x, y)
  • Solving systems of equations using systems

Explanation:

Step 1: Define Systems

x + 4y = 4

-x + 2y = 8

Step 2: Rewrite Systems

x + 4y = 4

  1. [Subtraction Property of Equality] Subtract 4y on both sides: x = 4 - 4y

Step 3: Redefine Systems

x = 4 - 4y

-x + 2y = 8

Step 4: Solve for y

Substitution

  1. Substitute in x: -(4 - 4y) + 2y = 8
  2. [Distributive Property] Distribute negative: -4 + 4y + 2y = 8
  3. Combine like terms: -4 + 6y = 8
  4. [Addition Property of Equality] Add 4 on both sides: 6y = 12
  5. [Division Property of Equality] Divide 6 on both sides: y = 2

Step 5: Solve for x

  1. Define original equation: x + 4y = 4
  2. Substitute in y: x + 4(2) = 4
  3. Multiply: x + 8 = 4
  4. [Subtraction Property of Equality] Subtract 8 on both sides: x = -4
User David Yates
by
5.1k points