On January $2,$ Smith Company paid $$26,100$ to purchase equipment that has a useful life of $9$ years. The equipment will be depreciated equally over the $9-$year period as depreciation expense. The cost of $$26,100$ is divided by the useful life of $9$ years to determine the amount of the yearly depreciation expense of $$2,900.$ If the appropriate adjusting entry is not made at the end of the year, what will be the effect on:

$($a$)$ Income statement accounts $($overstated$,$ understated, or no effect$)?$

$($b$)$ Net income $($overstated$,$ understated, or no effect$)?$

$($c$)$ Balance sheet accounts $($overstated$,$ understated, or no effect$)?$