A rule for estimating the number of board feet of lumber that can be cut from a log depends on the diameter of the log. To find the diameter, \mathrm{d} , required to get 7 board feet of lumber, we use the equation $\left( \frac { d - 4 } { 4 } \right) ^ { 2 }$=49 . Solve this equation for d. Are both answers reasonable?
A) 32,-24 ; No, only 32 feet is a reasonable answer.
B) 11,-28 ; No, only 11 feet is a reasonable answer.
C) 24,-32 ; No, only 24 feet is a reasonable answer.
D) 28,-28 ; No, only 28 feet is a reasonable answer.

Question

A rule for estimating the number of board feet of lumber that can be cut from a log depends on the diameter of the log. To find the diameter,  \mathrm{d} , required to get 7 board feet of lumber, we use the equation $\left( \frac { d - 4 } { 4 } \right) ^ { 2 }$=49 .  Solve this equation for d. Are both answers reasonable?
A)  32,-24 ; No, only 32 feet is a reasonable answer.
B)  11,-28 ; No, only 11 feet is a reasonable answer.
C)  24,-32 ; No, only 24 feet is a reasonable answer.
D)  28,-28 ; No, only 28 feet is a reasonable answer.

Quizplus · Accepted Answer

The diameter of a log cannot be negative, so the answer -24 is not reasonable.

A Rule for Estimating the Number of Board Feet of Lumber