All you do is solve for z. So 8z-13=7. To solve for a variable you have to do the opposite to cancel out the numbers on each side. First you add 13 over to 7 to cancel out 13 on the z side. So 8z=20 is what you have left. Then you divide 8 on both sides to cancel out 8 on the z side. what you are left with is z=2.5. Lastly you plug and check. 8(2.5) - 13 = 7, 20-13=7. And thats correct so z is 2.5.
Step-by-step explanation:
y=-2x+1 so we say (-2x+1)
we flip the equation by saying
-2x+1 -1=y+-1
-2x=y-1
Divide both sides by -2
-2÷-1 = y-1÷-2
so x=-1÷2 y=+1÷2
Answer:
C. Slope and 
Step-by-step explanation:
We're missing the graph itself, but I can make an educated guess:
- Assuming x = volume and y = mass:

density = mass/volume
x = volume = run
y = mass = rise
mass/volume = rise/run = slope
The slope of the line (assuming the graph is purely linear) represents mass/volume, which is the formula for density.
I had to Google the density of silver itself. Do the math from the graph for a more appropriate answer, as the graph may be less scientifically precise.
A discontinuity is a point that cannot exist because the x-coordinate would cause a problem in the equation. If you have a polynomial in the denominator, you must find which values of x would cause the polynomial in the denominator to evaluate to zero. Since division by zero is undefined, that would cause a discontinuity.
Let's look at your function.


is in the numerator. It is defined for every value of x. There is no problem there.

is in the denominator. This is a function defined for every value of x, but since it is in the denominator, we must exclude the x-value that would cause this polynomial to evaluate to zero.
We set it equal to zero and solve the equation for x.



For x = 0, the denominator has a value of zero, so at this point there is a discontinuity in function f(x).
The answer is: