Question

how to know how to solve a simultaneous equation. When do we plus when do we subtract and when do we multiply?​

Answer 1

Answer:

Look at the signs in front of the common coefficient. If the signs are different, add the equations together. If the signs are the same, subtract them. You can remember this as DASS – Different Add, Same Subtract.

Answer 2

Answer:

Look at the signs in front of the common coefficient. If the signs are different, add the equations together. If the signs are the same, subtract them. You can remember this as DASS – Different Add, Same Subtract.