A student is asked to calculate the value of 353 using the identity (x + y)3 = x3 + 3x2y + 3xy2 + y3. The student's steps are shown below. Step 1: 353 = (30 + 5)3; therefore, x = 30 and y = 5 Step 2: = (x)3 + 3(x)2(y) + 3(x)(y2) + (y)3 Step 3: = (27,000) + (a) + (b) + (125) Step 4: = 42,875 In Step 3, what are the values of a and b, respectively?