# Applications of linear equations

### Applications of linear equations

We always encounter situations that can be expressed in linear equations. Watch this lesson and learn how to solve linear equations word problems.

#### Lessons

• 1.
Find the equation of a line parallel to 3x + 5y = 9 with the same y-int as 4x -5y = 12

• 2.
Find the equation of a line perpendicular to 3x + 4y = 12 with the same x-int as 2x - 6y = 0

• 3.
Lines A & B are perpendicular and have the same x-int. The equation of line A is x + 2y - 4 = 0. Determine the y-int of line B.

• 4.
Alex bought 144 bagels for $80. His profit was$75 once he had sold 100 bagels. Find the equation that represents Alex’s profit P as a function of the number sold, n?

• 5.
A super computer still has the value of $80,000 after two years, and$50,000 after four years. Determine the purchase price of the super computers

• 6.
A house was purchased for $500,000. The owner expects the house to double in value in the next 12 years. Find the appreciation equation. • 7. The total cost of a car is the sum of the selling price, plus a sales tax of 5%, plus a$100 environmental fee.
i)
Express the total cost of the car as a linear function of the selling price.
ii)
What is the total cost of a car that sells for $56,000? iii) What is the selling price of a car whose total cost was$72,000?