Question

Answer the following questions. Make sure to show all your work. 1. When is it best to solve a system of equations using graphing? 2. When is it best to solve a system of equations using substitution? 3. When it is best to solve a system of equations using elimination? When it is 4. Solve the following system of equations graphically. y=3x+4 y=-2x-5

Answer 1

Answers

1. Use graphing when you have equations in y intercept form and when you have a graphing calculator or graphing app on line
Example
y = 3x +4
y = -2x -5

2. Substitution works best when you can manipulate your equations so you can have a variable on one side of the equation for substituting into the other equation
y = 3x +4
x = y + 1

3. Elimination works best when one of your variables is a + and a - so they will cancel or eliminate, allowing you to solve for one variable.
Example
2x + 4y = 2
-2x + 2y = 3

4. Solution is ( -1.8, -1.4) and the graph is attached with graphing points