Respuesta :

Space

Answer:

(9, 3)

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

  • Coordinates (x, y)
  • Solving systems of equations using substitution/elimination

Step-by-step explanation:

Step 1: Define Systems

-4x + 6y = -18

y = -2x + 21

Step 2: Solve for x

Substitution

  1. Substitute in y [1st Equation]:                                                                           -4x + 6(-2x + 21) = -18
  2. [Distributive Property] Distribute 6:                                                                 -4x - 12x + 126 = -18
  3. [Subtraction] Combine like terms:                                                                   -16x + 126 = -18
  4. [Subtraction Property of Equality] Subtract 126 on both sides:                     -16x = -144
  5. [Division Property of Equality] Divide -16 on both sides:                               x = 9

Step 3: Solve for y

  1. Substitute in x [2nd Equation]:                                                                         y = -2(9) + 21
  2. Multiply:                                                                                                             y = -18 + 21
  3. Add:                                                                                                                   y = 3
queenb13267

Answer:

x=9, y=3

Step-by-step explanation:

For this problem, you can sub the second equation for y in the first one.

This gives -4x+6(-2x+21)=-18, which can be expanded to -4x-12x+126=-18.

From there, you can collect like terms to get -16x+126=-18.

Subtracting 126 from both sides gives -16x=-144.

You want to isolate x by dividing both sides by -16, giving x=9.

You can sub 9 for x in either equation to work out y (I'm using the second one, as it is easier).

This gives y=-2×9+21, which can be solved to y=-18+21, or y=3.

**This question involves solving linear equations, which you may wish to revise. I'm always happy to help!

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