The Only Time I Want You To Use Substitution

This video tutorial explains when to use substitution for solving systems of equations. It highlights two scenarios: when both equations are solved for the same variable and when one equation has an isolated variable. The video provides examples for each case, demonstrating the substitution method step-by-step. It concludes with advice on choosing between substitution and elimination, and offers additional resources for further learning.

What are the two scenarios where substitution is recommended for solving systems of equations?

• When both equations are quadratic

• When both equations are linear

• When both equations have integer coefficients

• When both equations are solved for the same variable or one has an isolated variable

In the example where both equations are solved for the same variable, what is the first step in using substitution?

• Add the equations together

• Set the equations equal to each other

• Multiply the equations by a constant

• Subtract one equation from the other

When using substitution with an isolated variable, what should you ensure when substituting the expression?

• Multiply the expression by 2

• Use brackets around the expression

• Divide the expression by the coefficient of the variable

• Add 5 to the expression

What is the benefit of having a variable already isolated when using substitution?

• It allows for easier graphing

• It simplifies the substitution process

• It eliminates the need for further calculations

• It ensures the solution is always correct

What is the main reason the teacher suggests using substitution only in specific cases?

• Substitution is less reliable

• Substitution can be more work than elimination

• Substitution is more accurate

• Substitution is always faster