Answer:
The GCF of 7 and 12 is 1.
“Rate of change” means the same as “slope.”
In algebra, we use the word "slope" to describe how steep a line
is and slope can be found using the ratio rise/run between
any two points that are on that line.
Starting from the point that has the coordinate (-1, -1),
we rise go 1 unit down so our rise is -1 and run 3 units.
So our slope or rise/run is -1/3.
Y=mx+b, the b is your y-intercept so just rearrange your equation
y=(3/7)x+(2/7)
your y-intercept would be b) (2/7)
x/.75=x-56/0.4
0.4x=.75x-42
-0.35x=-42
x=120
I set up a proportion in which x=the tank when it is 3/4 full. When the tank is 3/4 full, solving the proportion tells us the x=120 litres. 120/3=40, and 120+40 is 160, showing that a tank completely full would indeed hold 160 litres.
Hope this helps!