Blue Company purchased machinery on January 1, 2025, for $97,600. The machinery is estimated to have a salvage value of $9,760 after a useful life of 8 years.

a) Compute 2025 depreciation expense using the sum-of-the-years'-digits method.

b) Compute 2025 depreciation expense using the sum-of-the-years'-digits method, assuming the machinery was purchased on April 1, 2025.

Need explanation for part B mainly.. help!