Which systems of equations are best solved using addition? 3 x plus 4 y3x+4y equals= 1515 yy equals= 4 x plus 154x+15 negative 3 x minus 3 y−3x−3y equals= minus−1515 3 x minus 3 y3x−3y equals= minus−1515 3 x plus 4 y3x+4y equals= minus−1515 2.6 x plus 3.6 y2.6x+3.6y equals= 1515 2.6 x minus 3.6 y2.6x−3.6y equals= 1515 2.6 x minus 3.6 y2.6x−3.6y equals= minus−1515
