Question

How can you decide which variable to solve for the first when you are solving a linear system by substitution

Answer 1

When solving a linear system by substitution, choose the variable that is already isolated in one of the equations. Substitute the value of that variable into the other equation.

Step-by-step explanation:

When solving a linear system by substitution, it is important to decide which variable to solve for first. One strategy is to choose the variable that is already isolated in one of the equations. This makes it easier to substitute the value of that variable into the other equation.

For example, consider the system:

Equation 1: x + 2y = 5

Equation 2: 3x - y = 2

In this case, Equation 1 is already isolated for x, so it would be a good choice to solve for x first. By substituting the expression for x from Equation 1 into Equation 2, you can solve for the remaining variable y. Once you have the value of y, you can substitute it back into Equation 1 to find the value of x.

Answer 2

The variable having largest coefficient is solved first.

Step-by-step explanation:

The variable having greater coefficient is solved first because we can substitute the value of smaller coefficient variable easily as compared to the greater one.

Because in substitution method we first substitute the value of coefficient which has smallest coefficient and as a result the coefficient with greater coefficient is solved.