Question

When solving systems of equations, how do you determine what method to use?

Answer 1

If any equation has a variable which is a multiple of another variable. Use elimination.

Answer 2

For instance:

3x + 2y = 106
-12x + 5y = 530

equation one's x is a multiple of equation 2's x.

Answer 3

alrighty

Answer 4

Use substitution if you have one variable already known/ alone
For instance:

y = 45
3x + 7y = 116

Answer 5

Also you can use substitution if you have a singular variable by isolating that variable:
For instance:

3x + 17y = 160
9x + y = 107

Isolate the singular y in the second equation:

y = 107 - 9x.