What is the primary goal when solving a system of equations?

To find the values of the variables that satisfy all equations in the system simultaneously.

In the substitution method, what is the first step you should take?

Solve one of the equations for one variable in terms of the other variable.

Either a or b, because they both have a coefficient of 1 or -1.

Substituting back into the same equation would only result in an identity (e.g., x = x) and would not help solve for the variables.

Grade 9th Grade · Math · 45 min· Big Ideas Math

I can solve a system of equations using substitution.

Khan Academy · 9:21

Solving linear systems by substitution | Algebra Basics | Khan Academy

3 key concepts

1
The substitution method involves solving for one variable in one equation and substituting that expression into the other equation.
2
When using substitution, the goal is to create a single equation with one unknown variable that can be solved.
3
After finding the value of one variable, substitute it back into either of the original equations to solve for the remaining variable.

8 questions · Multiple choice & Short answer

Quick comprehension check

“Solve the following system of equations using substitution: y = 2x + 1, 3x + 2y = 16. Show all steps.”

Get all 3 ready-to-use resources:

Teacher GuideComplete lesson plan

Student DocPrintable student handouts

SlidesReady-to-use presentation