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Solve the following system of linear equations.

3x - 5y = - 39

6x + 2y = - 42

Select one:

A. (-2, - 14)

B. (-8, 3)

C. no solution

D. infinitely many solutions

+4
Answers (2)
  1. 9 June, 10:10
    0
    B

    given the 2 equations

    3x - 5y = - 39 → (1)

    6x + 2y = - 42 → (2)

    multiply (1) by - 2

    - 6x + 10 y = 78 → (3)

    add (2) and (3) term by term to eliminate x

    (6x - 6x) + (2y + 10y) = ( - 42 + 78)

    12y = 36 (divide both sides by 12)

    y = 3

    substitute this value in either of the 2 equations and solve for x

    (2) → 6x + 6 = - 42 (subtract 6 from both sides)

    6x = - 48 (divide both sides by 6)

    x = - 8

    solution is ( - 8, 3) → B
  2. 9 June, 10:11
    0
    To solve a problem like this, you will need to use substitution or elimination. For the sake of an example I will solve this using substitution.

    First, solve one of the equations for x or y:

    3x-5y=-39

    3x=-39+5y

    X = (-39+5y) / 3

    Then substitute for the value of x in the second equation:

    6x+2y=-42

    6 ((-39+5y) / 3) + 2y=-42

    Solve for y:

    -78+10y + 2y=-42

    -78+12y=-42

    12y=36

    Y=3

    Once you've solved for y, you can plug in it's value to find x:

    X=-39+5 (3) / 3

    X=-24/3

    X=-8

    So, we can conclude that the correct answer is B. (-8,3)
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