@tranphuonganh97 as u said that”When Nancy purchase new equipment, her Cash (Asset) decreases 1,200 while her non – current Asset increases 1,200. So this transaction seems to have no effect to accounting equation., so just like that nancy sold goods worth 7500 it means these are our recievables and it decreases our asset/inventory by 7500 but on the other hands it also increases our receivables by 7500 and u should also b familier that receivables are our current asset so this also has no effect.so the correct ans is b