Seudónimo Seudónimo 01-05-2016 Mathematics contestada The work of a student to solve a set of equations is shown: Equation A: y = 15 – 2z Equation B: 3y = 3 – 4z Step 1: –3(y) = –3(15 – 2z) [Equation A is multiplied by –3.] 3y = 3 – 4z [Equation B] Step 2: –3y = 15 – 2z [Equation A in Step 1 is simplified.] 3y = 3 – 4z [Equation B] Step 3: 0 = 18 – 6z [Equations in Step 2 are added.] Step 4: 6z = 18 Step 5: z = 3 In which step did the student first make an error