Answer:
If y(t) is the mass (in mg) remaining after t years, then y(t) = y(0) (0.5)^{t/T} = 400 (0.5)^{t /4}, where T is the half-life period and y(0) is the amount at t = 0 years (initial).
Then at t = 20:
y(20) = 400 (0.5)^{20 /4} = \text{12.5 mg}
Step-by-step explanation:
Answer: y = 2/1x + 2
Step-by-step explanation:
A slope of 2 means rising 2 and run 1 on a graph. This would make x = 2/1. The + 2 allows the line to pass through (0,2) and therefore it will also pass through (-2,-2).
Answer:
y = x + 5
Step-by-step explanation:
1) First, find the slope of the line 
. We can do this by setting it up in slope-intercept form, represented by the equation 
. Whatever 
or the coefficient of the x-term is will be the slope. Isolate y in the equation:
So, the slope of the given equation is 1. Parallel lines share the same slope, thus the slope of the new line will be 1 as well.
2) Now, use the point-slope formula 
to write the equation of the line in point-slope form. Substitute values for , 
, and 
in the formula.
Since is the slope, substitute 1 for it. Since and represent the x and y values of one point the line passes through, substitute the x and y values of (-6, -1) into those places as well. Then, isolate y in the resulting equation to put the equation in slope-intercept form and find the answer:
Answer:
The solutions are:
Step-by-step explanation:
To find the solutions to the equation 
you need to:
- Factor
Break the expression into groups
Factor out 
from 
Factor out 3 from 
- Factor
Therefore
Using the Zero Factor Theorem:
Answer:
-1.5 is the gradient (m), correct equation: y= -1.5x-7
Step-by-step explanation:
m=y2-y1/x2-x1
for getting the correct equation, input y, x and m in the equation y=mx+c to find c
