N = 75,000*(1/2)^(h/4) . . . . N = number alive; h = hours
3000 = 75000*(1/2)^(h/4) . . . . . substitute given numbers
1/25 = (1/2)^(h/4) . . . . . . . . . . . . . .divide by 75000
log(1/25) = (h/4)*log(1/2) . . . . . . . take the log, then divide by the coefficient of x
h = 4*log(1/25)/log(1/2) ≈ 18.6 . . . . hours
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Of course log(1/25) = -log(25) = -2log(5), so the expression for h can be written as h = 8log(5)/log(2)
Answer:
2.yes 3.no
Step-by-step explanation:
The <em>correct answers</em> are:
A) Both can be solved by graphing;
C) Both can be solved by substitution; and
D) Both have solutions at the points of intersection.
Explanation:
Just as a system of linear equations can be solved by graphing, a system of quadratic equations can as well. We graph both equations. We then look for the intersection points of the graphs; these intersection points will be the solutions to the system.
We can also solve the system by substitution. If we can get one variable isolated, we can substitute this into the other equation to solve.
Answer:
True
Step-by-step explanation:
(x + 4)² = (x + 4) (x + 4)
x² + 4² = x² + 16
E because 8*8=64 so 8/49*8/49 = 64/49
