Choose all that give a correct first step to solve the system of equations by the elimination method. equation a: 3x + 4y = 52 equation b: 5x + y = 30 multiply equation b by ? 4 equation a: ? 2x + 3y = ? 1 equation b: x + 5y = 25 multiply equation b by 2 equation a: 2x + y = 2 equation b: ? 3x + 3y = 10 multiply equation a by 5 equation a: 4x + y = 3 equation b: 6x + 3y = 9 multiply equation a by ? 3