To determine the price per pound of beef when it was equal to the price per pound of chicken, determine the value of x (the number of weeks after July 1) when the two prices were equal.
The prices were equal when
b=c; that is, when
2.35+0.25x=1.75+0.40x.
This last equation is equivalent to
0.60=0.15x, and so
x==4.
Then to determine b, the price per pound of beef, substitute 4 for x in
b=2.35+0.25x, which gives
b=2.35+0.25(4)=3.35 dollars per pound.
Choice A is incorrect.
It results from using the value 1, not 4, for x in
b=2.35+0.25x. Choice B is incorrect.
It results from using the value 2,not 4, for x in
b=2.35+0.25x. Choice C is incorrect.
It results from using the value 3, not 4, for x in
c=1.75+0.40x.