what does it mean to solve for a variable when the solution is not a
number?

It might help you if you knew what  variable was.

A variable can be (x) or (y) or anything really it just a letter the represents a number.

In this case, when it says solve for a variable it means find what the variable equals. For example:

4x + 18 = 2

here you need to find the value of X.

x = -5

X equals negative 5 because you multiply the variable to the number:

4 x -5 = -20

-20 + 18 = 2

making the

4(-5) + 18 = 2

x = -5

(hope this helps)

x=-2

infinite number of lines, so there is an infinite number of equations.

step-by-step explanation:

there are an infinite number of line that passes through the point (-2,5)

x=-2   is one line that passes through the point

y = 5 is another line that passes through the point

(these two lines are perpendicular to each other).

since the number of   numbers are infinite and the slope is the ratio of two numbers,(change in y over change in x) we can have an infinite number of slopes.     our only condition is that it passes through the point (-2,5)