Question

When eliminating in systems of equations, how do you know when to add or subtract?

a) Always add
b) Always subtract
c) Depends on the coefficients
d) Neither, always multiply

Answer 1

When eliminating in systems of equations, you need to add or subtract in order to eliminate one of the variables. The decision to add or subtract depends on the coefficients of the terms you want to eliminate.

Step-by-step explanation:

When eliminating in systems of equations, you need to add or subtract in order to eliminate one of the variables. The goal is to create an equation where one variable cancels out when the two equations are added or subtracted. Whether you add or subtract depends on the coefficients of the terms you are trying to eliminate.

Here are the steps to determine whether to add or subtract:

1. Identify the variable you want to eliminate.
2. Look at the coefficients of that variable in both equations.
3. If the coefficients have the same sign, subtract the equations to eliminate the variable.
4. If the coefficients have opposite signs, add the equations to eliminate the variable.

By adding or subtracting the equations, you can eliminate one variable at a time and solve the system of equations.