Which system of equations has the same solution as the system below? 2x+2y=16 and 3x-y=4

Of the ones listed here, the factor that had the greatest impact on the eventual destruction of native americans' ways of life was the development of the a) automobile. b) highway. c) railroad. d) steamboat.

(-y to the power of 2 - 4y- to the power of 2 -6 y +3)

Me because i don't understand how to do it.: )