When will you use linear equations in real life?

Everyday budgeting and other financial issues often use linear equations. Linear equations involve two values that change according to a consistent pattern.

In an equation, the consistent value is called the rate of change or slope, and it is a known value.

Linear equations can solve practical matters in life, such as:

• The equation for a cellphone bill with a flat rate of $25 per month plus 25 cents per message would be y = 25 + 0.25x, with x as the number of messages and y as the monthly cost.
• The equation for taxi cab fares based on a set fee of $2 per mile would be y = 2x, with x as the amount of electricity used and y as the amount of the bill.