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Select the best possible first step to solving the system by first eliminating the y variable.


4x – 5y = 4

3x + 2y = –20


A. None of the above

B. Multiply the first equation by 2 and multiply the second equation by 5.

C. Multiply the first equation by 2 and multiply the second equation by –5.

D. Multiply the first equation by –2 and multiply the second equation by 5.

Respuesta :

Blacklash

Answer:

 Option B is the correct answer.

Explanation:

 We have equations

        4x – 5y = 4   ----------------- equation 1

        3x + 2y = –20   ----------------- equation 2

 Now we are eliminating y.

     equation 1 x 2 gives

         8x - 10y = 8   ----------------- equation 3

    equation 2 x 5 gives

         15 x + 10 y = -100   ----------------- equation 4

   Now adding equation 3 and equation 4

           8x - 10y + 15 x + 10 y = 8 - 100

            23 x = -92

 So, y got eliminated

 Here we multiplied the first equation by 2 and multiply the second equation by 5 to eliminate y.

Option B is the correct answer.

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