The equation [tex]p=1.95 t^2 + 12.25 t + 125[/tex] approximates the average sale price [tex]p[/tex] of a house (in thousands of dollars) for years [tex]t[/tex] since 2010.

What is the best estimate for the price of the house in the year 2021?

A. [tex]$\$[/tex] 496,000[tex]$
B. $[/tex]\[tex]$ 553,000$[/tex]
C. [tex]$\$[/tex] 614,000[tex]$
D. $[/tex]\[tex]$ 679,000$[/tex]



Answer :

To determine the best estimate for the price of a house in the year 2021 using the given quadratic equation [tex]\( p = 1.95 t^2 + 12.25 t + 125 \)[/tex], follow these steps:

1. Identify the value of [tex]\( t \)[/tex]: Since [tex]\( t \)[/tex] represents the number of years since 2010, calculate [tex]\( t \)[/tex] for the year 2021.
[tex]\[ t = 2021 - 2010 = 11 \][/tex]

2. Plug [tex]\( t = 11 \)[/tex] into the equation: Substitute [tex]\( t \)[/tex] into the quadratic equation to find [tex]\( p \)[/tex].
[tex]\[ p = 1.95(11)^2 + 12.25(11) + 125 \][/tex]

3. Calculate the square and product terms:
[tex]\[ 11^2 = 121 \][/tex]
[tex]\[ 1.95 \times 121 = 235.95 \][/tex]
[tex]\[ 12.25 \times 11 = 134.75 \][/tex]

4. Sum the results to find [tex]\( p \)[/tex]:
[tex]\[ p = 235.95 + 134.75 + 125 = 495.7 \text{ (in thousands of dollars)} \][/tex]

5. Convert [tex]\( p \)[/tex] to dollars: Since [tex]\( p \)[/tex] is given in thousands of dollars, convert it to dollars:
[tex]\[ p = 495.7 \times 1000 = 495,700 \text{ dollars} \][/tex]

6. Round to the nearest thousand: To match the answers provided, round the result to the nearest thousand:
[tex]\[ 495,700 \approx 496,000 \][/tex]

Therefore, the best estimate for the price of the house in year 2021 is [tex]\( \boxed{496,000} \)[/tex] dollars.