The second to last option is correct
1200 in the first month 1285.48 in the second and 1370.96 in the last as it goes up equally by 85.48 each month
The first step would be to isolate a variable (solve for a variable)....so u will have something to sub into the other equation
An equation expresses the relation between variables. A relation between y and x can be drawn as a graph in the xy plane.
In order to do that, you want to "plug in" a value for x, and then get the result as a value for y. With an equation that expresses y in terms of x, you can do just that. For example, plug in the value x=3 in the equation y=2x+4 easily gives you y=10. You plot the point (3,10) and repeat for different x.
If y is not clearly expressed in terms of x, you get equations like: 2x + 4y + x/y = 0. You cannot plug in an x and calculate a y in an easy way.
Most of the time you'll be able to rewrite the equation in the right "pluggable" form. In fact, when you have an equation in this form, it maps one to one to a function f(x). y=2x+4 and f(x)=2x+4 is kind of the same thing. "f is a function of x" and "y is expressed in terms of x" are similar statements.
This is not true because some states do not have state tax. For example , Nevada, Texas, Florida and Washington do not have state tax .
