Answer:This is a tricky question that Reina and Sam are multiplying (84)5 (73)9 and their work are (84)5 (73)9 = 84 + 573 + 9 = 89712 Reina's (84)5 (73)9 = 84-573-9 = 820727 Sam's Actually they are doing or multiplying using exponents. Reina's work (8*)s(7³)º=8*+5+ 73+9= 8° 712 This is incorrect because she added exponents instead of multiplying exponents Sams work (8*)5 (7³)º=84x5 73x9= 820 727 This is correct because Sam multiplied exponents correctly Exponents are multiplied not added.