Chapter 4:Algebra, 4.6:Solving Simultaneous Linear Equations by Elimination and Subsititution

What are simultaneous equations?

Two or more equations containing the same unknowns that must be true at the same time

What does solving simultaneous equations mean?

Finding the values of the variables that satisfy all the equations

What is the substitution method?

Rearranging one equation to make one variable the subject

What is the first step in substitution?

Make one variable the subject of one equation

What do you do after substituting?

Solve the resulting equation for one variable

How do you find the second variable after solving for one?

Substitute the known value back into an original equation

What is the elimination method?

Combining equations to eliminate one of the variables

What should you do before using elimination?

Line up the variables and make the coefficients of one variable equal if necessary

How do you eliminate a variable?

Add or subtract the equations so that one variable cancels out

When is substitution useful?

When one variable is already the subject or can easily be made the subject

When is elimination useful?

When the coefficients of one variable are already equal or can easily be made equal

What should you do if you multiply an equation by a number?

Multiply every term on both sides by that number

Why must you be careful when subtracting equations?

Signs can change

How can you check a solution to simultaneous equations?

Substitute both values into the original equations and check that both are true