Which of the following is a solution to the system of two equations y = 3x – 7 and 4x – 5y = -20?

Question

Which of the following is a solution to the system of two equations y = 3x – 7 and 4x – 5y = -20?

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Tài Đức 5 years 2021-08-22T08:20:04+00:00 1 Answers 68 views 1

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  1. Neala
    0
    2021-08-22T08:21:58+00:00
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    Answer:

    x = 5, and y = 8

    Step-by-step explanation:

    You can solve this system by solving either of the equations for either x or y, and substituting that into the other.

    Since the first equation is already defined for y, let’s substitute that into the second equation:

    4x – 5y = -20

    4x – 5(3x – 7) = -20

    4x – 15x + 35 = -20

    4x – 15x = -20 – 35

    -11x = -55

    x = 5

    We can then plug that into either of the original equations to find y:

    y = 3x – 7

    y = 3 * 5 – 7

    y = 15 – 7

    y = 8

    We can also verify our answer by plugging one of the values into either of the original equations and seeing what we get:

    4x – 5y = -20

    4x – 5 * 8 = -20

    4x – 40 = -20

    4x = 20

    x = 5

    So we know the answer is correct.  x is equal to five, and y is equal to eight.

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