How will we get to know if we need to subtract or add the equation in elimination method?

How will we get to know if we need to subtract or add the equation in

1.	How will we get to know if we need to subtract or add the equation in elimination method?
Answer» The\xa0elimination method\xa0of solving systems of equations is also called the addition\xa0method. To solve a system of equations by\xa0elimination\xa0we transform the system such that one variable "cancels out". ... In order to solve for y, take the value for x and substitute it back into either one of the original equations. In the\xa0elimination method you\xa0either\xa0add\xa0or\xa0subtract\xa0the\xa0equations\xa0to get an\xa0equation\xa0in one variable.\xa0When\xa0the coefficients of one variable are opposites\xa0you add the equations\xa0to\xa0eliminate\xa0a variable and\xa0when\xa0the coefficients of one variable are equal\xa0you subtract\xa0the\xa0equations\xa0to\xa0eliminate\xa0a variable.