- 3x -1= 3x -7 Like terms -3x -3x = -7 + 4 A negative and a negative is a positive -3x + - 3x = -6x because a positive and a negative is a negative -7 + 1 = - 6 Hence - 6 x = -6 Divide both sides by -6 Which gives u X = 1 Now substitute x = 1 into one of the original equations Y = 3x - 7 Y = 3*1 - 7 Y = 3 - 7 Look at the bigger number sign Therefore Y = - 4 So when x = 1, y = -4 It’s really the same for the rest of the questions to be honest