Answer:
D)
Step-by-step explanation:
f(x) = x^2 -14x -72
0=x^2 - 14x-72
0=x^2 - 18x+4x-72
0=x(x-18)+4(x-18)
0=(x-18)(x+4)
x-18=0 or x+4=0
x1=18 or x2=-4
asis of symmetry: x=(x1+x2)/2
x=(18+(-4))/2
x=14/2
x=7
It is in the form y = mx + b. therefore it is linear.
well, we know that 213.90 includes the 15% gratuity, so if the meal price was say "x", namely that is the 100%, and we add 15% to that, then 100% + 15% = 115%, so 213.90 is really the 115%.
now, if 213.90 is the 115.%, what is "x"? the 100%.

so since we know the meal without the tip is 186 bucks, the tip was then 213.90 - 186 = 27.90.
but they got extra potato wedges with butter and the waitress was wearing her best hat, they added $20 more, so the tip ended up as 27.90 + 20 = 47.90.
now, if the cost of the meal was $186 and that is the 100%, what is 47.90 off of it in percentage?

Since you have the answers given, just track their walking.
After one hour, one guy has covered 3mi and the other 4mi, which is in total 7, not 14
After 2 hours, one guy has covered 6mi and the other 8mi, which is 14mi
The algebraic way would be:
3x +4x = 14 *x being the hour
7x = 14
x =2