Answer:
Opposite sign
Step-by-step explanation:
You can find this because when a point is reflected across the x-axis, its y-coordinate changes its sign. The same is true when reflected across the y-axis. It's x coordinate changes its sign.
You take the first equation and make a value for y. So 6x + y =7 change it to :
y = -6x + 7
Now in the second equation replace the “y” with -6x +7 this is what it means to use substitution method . Your combined equation will now be :
8x + 9(-6x + 7) =17
Now do distributive property and you get :
8x + -54x +63 =17
Now combine like terms ;
-46x +63 =17
-46x =-46
x = 1
Now replace 1 for X value and we can get the value of Y .
Y=1
X=1
About 92 days are taken for 90 % of the material to <em>decay</em>.
The mass of radioisotopes (
), measured in milligrams, decreases exponentially in time (
), measured in days. The model that represents such decrease is described below:
(1)
Where:
- Initial mass, in milligrams.
- Current mass, in milligrams.
- Time constant, in days.
In addition, the time constant is defined in terms of half-life (
), in days:
(2)
If we know that 
, 
and 
, then the time required for decaying is:
About 92 days are taken for 90 % of the material to <em>decay</em>.
We kindly invite to check this question on half-life: brainly.com/question/24710827
Answer:
It should be A
Step-by-step explanation:
I hope this helps
We have to find the slope of the line that passes through this points:
p1(-2,15), p2(-8,-5)
the slope of a line through two points is calculated like this:
m = (y2 - y1)/(x2 - x1)
where x1,y1,x2,y2 are the coordinates of the two points, so we have:
m = (-5 - 15)/(-8 - (-2))
m = (-20)/(-8 + 2)
m = -20/-6
m = 10/3
that is the line slope
