Answer:
c
Step-by-step explanation:
Answer:
7%
Step-by-step explanation:
Answer:
Step-by-step explanation:
Given:
Given polynomial function is.
Hours 
We need to find the concentration of the antibiotic after 3 hours.
Solution:
Rewrite the given polynomial function as.
Substitute in given polynomial function.
Therefore, the concentration of the antibiotic after 3 hours .
The quadratic formula is x=(-b+-sqrt(b^2-4(a)(c)))/2a
Using the quadratic formula, we get:
x=(-(-8)+-sqrt((-8)^2-4(15)(1)))/2(1)
x=(8+-sqrt(64-60))/2
x=(8+-sqrt(4))/2
x=(8+-2)/2
x=10/2 and x=6/2
x=5 and x=3
We could do it way faster by completing the square:
x^2-8x+15=0
(x-5)(x-3)=0
x=5 and x=3
Hope both methods make sense! BTW, the +- thing means add or subtract
The correct answer is -70 if you substitute in -7 for c the equation will be = -63 -7 = -70
