Equations are used more in every day life. We live in a capitalist society. We deal with money everyday and ambiguous costs are not acceptable. Whenever you buy or sell an item it's always for an calculated value never a range of values.
For literal equation example; How to calculate the price of an item, p after a discount rate d
x = p/(1-d)
p = x(1 - d)
Literal equations you solve for the formula, the new price of the item, p. So you have a general formula for finding the new price of an item on sale.
p = x(1 - d)
when you have the formula you can then put in the values, calculate the discount price of items see relationships between variables.
if the original cost x is 100$ and discount is 10% how much will the item cost?
p = 100(1 - 0.10)
p = 100(0.9)
p = $90
In a one or two step equation there are numbers and only one unknown value to solve for. These can be solved in one or two steps according to the name.. There are no values to substitute for variables.
One step equation: (unknown solved for in one step)
5x = 25
divide by 5
x = 5
Two Step equation: (unknown solved for in two steps)
2x - 8 = 10
add 8
2x = 18
divide by 2
x = 9