Hi!
First you need to put these in y=mx+b form.
2x - 5y = -16
Subtract both sides by (2x), giving you -5y= -16-2x
Divide by both sides by (-5) to get y by itself, giving you y= (16/5) + (2/5)x
4x - 10y= -16
Follow the same steps: first subtract by (4x), giving...

Flourine :)
Using the periodic table helps
this webpage of a periodic table with the electron configurations may help you http://chemwiki.ucdavis.edu/@api/deki/files/4226/=PeriodicTable2.jpg
Good luck!

For your first question: 3X- 7 = 3 (x = 1) I'm not sure if it's a typo and the equal sign should be a minus sign.
For the second question, is that three separate questions?
For your third question: solve for y first (isolate it out)
so subtract 2x from both sides giving you:...

You can accomplish this in a couple ways.
Without calculator: make a set of data points by inputting values (-2, -1, 0, 1, 2) for x to figure out the corresponding value for y. After you plot the points. For an example: y=5x so the data set would be: (-2, -10) (-1, 5) (0,0), (1, 5),...

Hi so I think if this is you question: 3x/(4-2x)/3 = (1/2), then solving for x:
1.)Multiply both sides by 3, giving you
3x/(4-2x)= 2/3
Break down: multiplying the left side of the equation removes the 3. (1/2)*3 = 2/3
2.) Now you have 3x/(4-2x)= 2/3 so you can cross multiply...