Answer:
profit to be taxable will be  $300,000
Step-by-step explanation:
Matt home cost = $150,000
Matt sold his home for = $450,000
so,
cost price will  be  $150,000
selling price will be $450,000
          profit = selling price - cost price
          profit  =  $450,000  -  $150,000
          profit  =  $300,000
hence the taxable amount for his home this year will be  $300,000