ANSWER
The equation is

EXPLANATION
The equation of the line that passes through the point (-1,3) and (1,4) can be found using the formula,

where


is the slope and

is a point on the line.
The equation of the line becomes,

Multiply through by 2 to get,.

Or
<span>To regroup 378 x 6, you must first establish the place values of each digit. 3 has a place value of 300, because it is in the hundreds column; 7 has a place value of 70 because it is in the tens column; 8 has a place value of 8 because it is in the units column. This means you can regroup 378 x 6 as (300 x 6) + (70 x 6) + (8 x 6). This makes 2,268. </span>
The common denominator is 12, the lowest number that has both six and four as factors.
Replace N with 6
6(6+1)(2(6)+1) / 6
(6*7*13) / 6
546 / 6 = 91
Answer is C
Radioactive half-life is the time it takes for half an amount of radioactive material to decay into something else. In this case, it is assumed that the decay product is not radioactive or otherwise hazardous.
We must use the radioactive decay formula to determine at what time the radiation reaches a safe level.
A = Ao[e^(-0.693)(t)(t 1/2) where t 1/2 is the half-life, t is elapsed time, Ao is the original quantity, A is the future quantity.
We are given a half-life of 2.4 days , an Ao of 1.25 and an A of 1.00:
1.00 = (1.25)e^(-0.693)(2.4)t
1.00/1.25 = e^(-1.6632)t
0.8 = e^(-1.6632)t
t = 0.135 days = 3 hrs 15 min
This is the amount of time to a "safe level" using only radioactive decay, not venting or other means.