The quadratic formula is:
and 
In this case, a = 2, b = -3, and c = -7
So, we can plug in the numbers to get:
and 
Simplifying, we get:
and 
You need to use a calculator to find what these would be in decimal form. The answer, rounded to the nearest tenth, is: x = 2.8, x = -1.3
2 * x/100 = 8
x/100 = 4
x = 400
400%
Answer:

Step-by-step explanation:
Let the function of quantity in the lung of air be A(t)
So 
so, A(t) = Amax sin t + b
A(t) = 2.8t⇒ max
A(t) = 0.6t ⇒ min
max value of A(t) occur when sin(t) = 1
and min value of A(t) = 0
So b = 0.6
and A(max) = 2.2

at t = 2 sec volume of a is 0.6
So function reduce to

and t = 5 max value of volume is represent
so,

when t = 5

so the equation becomes

Answer:
4.91 is the answer
Explanation:
4.908 the hundredths place is the 0, and 8 is greater than 5, so it would become 4.91
In a calculator you would take 82 * 0.63 which equals 51.66