Your answer is D because 10*2 is 20 and 6*2 is 12 so 12 out of the next 20 customers will purchase a sandwich.
0=4(x²+8x+16)-12
0=4x²+32x+64-12
0=4x²+32x+52
0=x²+8x+13
D=b²-4ac
D=64-52=12
x=(-b-√D)/2a
x=(-b+√D)/2a
x=(-8-2√3)/2= (-2(4+√3))/2= -(4+√3)
AND
x=(-8+2√3)/2=-2(4-√3)/2= -(4-√3)
Answer:
210 beats
Step-by-step explanation:
28 beats per 4 seconds
28 ÷ 4 = 7
7 beats per second
7 beats · 30 seconds
= 210 beats