Solving Systems of Equations Using the Elimination Method by Subtraction
Another way to eliminate terms that are additive inverses is by subtraction.
Practical Problem: Boat Speed and River Currents
A word problem involving rate, time, and distance is solved step-by-step using the elimination method.
Problem: The Perimeter of a Rectangle
Writing a system of equations to find the length and width of a rectangle, given the perimeter, and using the formula for finding the perimeter of a rectangle.
Practical Problem: The Length of the Spring on a Scale
Using the elimination method to solve a practical problem involving a scale, a spring, and some weights.
Solving the Same Rate-Time-Distance Problem Using One and Two Variables
Two different ways to write an algebraic equation for the same word problem involving rate, time, and distance are compared.
Solving the Same Word Problem Using One and Two Variables
Three different approaches to solving the same practical problem are demonstrated. Two approaches using one variable and a two-variable system all produce the same solution to the question of how many balcony seats and how many floor seats can be so...
Solving Systems with Fractions in the Equations
Systems of equations that contain fractions can be difficult to work with. Clearing the fractions in such a system by multiplying each equation by the least common denominator of the fractions in the equation can be a good strategy to employ.
Rewriting Equations in Order to Use the Elimination Method
Using the elimination method to solve a system of equations will sometimes require rewriting one of the equations.
Practical Problem: Homes and Apartments on 100 Acres
Calculating the number of houses and apartments that can be built on a 60-acre parcel of land given the amount of land allowed for each living unit is expressed in a system of equations involving fractions and solved using the least common denominat...
Solving a Word Problem Using Two Variables
Writing and solving a word problem using a two-variable approach.