Question

Bailey writes the expression g2 + 14g + 40 to represent the area of a planned school garden in square feet. If g = 5, what are the dimensions of the school garden?

20 feet by 2 feet
10 feet by 4 feet
12 feet by 7 feet
15 feet by 9 feet

Answer 1

The expression is
`A=g^2 + 14g + 40`.

`D=14^2-4\cdot 40=196-160=36 \\ √(D)=6 \\ q_(1,2)= (-14\pm 6)/(2) =-4,-10`.
Then
`A=g^2 + 14g + 40=(g+4)(g+10)`.
The width is g+4, the length is g+10.
When g=5,
g+4=9 ft and g+10=15 ft.
Answer: correct choice is D.