Question

Use elimination to solve the system for 4x + 7 y equals -14 + 8 x + 5 y equals 8 for x​

Answer 1

9514 1404 393

Answer:

  (x, y) = (3.5, -4)

Step-by-step explanation:

Elimination is easiest if one of the coefficients of a variable is a multiple of the other coefficient of the variable. Here, we have x-coefficients of 4 and 8, so it will be easiest to eliminate x.

Subtract the second equation from 2 times the first.

  2(4x +7y) -(8x +5y) = 2(-14) -(8)

  9y = -36 . . . . . simplify

  y = -4 . . . . . . . divide by 9

  4x +7(-4) = -14 . . . . substitute for y in the first equation

  4x = 14 . . . . . . . add 28

  x = 3.5 . . . . divide by 4

The solution is (x, y) = (3.5, -4).