3x - 1 = 3x -1 because it's reflecting itself
I believe it is the ratio 3 : 1.
<u>18 students chose the turkey sandwich</u>.
Since the class has a total of 24 students, we can deduce that <u>6 students chose the vegetarian sandwich</u>.
This gives us a ratio of 18 : 6.
When simplified, we get a ratio of 3 : 1.
Literal equation:
we know that
literal equation is equation of more one variable
for example: 
And we can solve such equations only if we are given two such equation
because it has two variables
One variable equation:
such equation has single variables
for example:

we don't need any other equation
we can solve for variables from single equation itself
because it has only one variable that is x
Find the sum of -3a and 5a -3
-3a + (5a-3)
2a-3