# How do you decide which equation to use for substitution?

## How do you decide which equation to use for substitution?

The method of solving “by substitution” works by solving one of the equations (you choose which one) for one of the variables (you choose which one), and then plugging this back into the other equation, “substituting” for the chosen variable and solving for the other. Then you back-solve for the first variable.

How do you find the POI of two equations?

How Do I Find the Point of Intersection of Two Lines?

1. Get the two equations for the lines into slope-intercept form.
2. Set the two equations for y equal to each other.
3. Solve for x.
4. Use this x-coordinate and substitute it into either of the original equations for the lines and solve for y.

How do you solve problems with substitution?

The method of substitution involves three steps:

1. Solve one equation for one of the variables.
2. Substitute (plug-in) this expression into the other equation and solve.
3. Resubstitute the value into the original equation to find the corresponding variable.

### What is it called when two lines cross?

Two or more lines that meet at a point are called intersecting lines.

How do I calculate poi?

To find the point of intersection algebraically, solve each equation for y, set the two expressions for y equal to each other, solve for x, and plug the value of x into either of the original equations to find the corresponding y-value. The values of x and y are the x- and y-values of the point of intersection.

How do you explain substitution method?

#### How do you use the substitution method?

Substitution Method Steps

1. Simplify the given equation by expanding the parenthesis.
2. Solve one of the equations for either x or y.
3. Substitute the step 2 solution in the other equation.
4. Now solve the new equation obtained using elementary arithmetic operations.