Solving Systems of Equations Choose the Best Method

Solve this system by substitution.

• (1, -4)

• (1, 4)

• (-4, -7)

• (-7, -4)

What is the solution to this system of equations?

• (4, -1)
• (-1, 4)
• (-4, 1)
• (-4, -1)

The first step in solving using the substitution method is __________.

• get x by itself
• get y by itself
• get either variable by itself
• add the equations together

Choose the best method for solving this system of equations:

Y = 2X +7

Y = 5X +4

• I should solve this system of equations using graphing because both equations are in slope-intercept format (Y=MX+B).

• I should solve this system of equations using substitution because one of the equations tells me “X=____”, or “Y =____”

• I should use elimination because both equations are in standard form (example: 2X + 3Y = 10)

Choose the best method for solving this system of equations:

X = 37Y + 1656

27X + 54Y = 1993

• I should solve this system of equations using graphing because both equations are in slope-intercept format (Y=MX+B).

• I should solve this system of equations using substitution because one of the equations tells me “X=____”, or “Y =____”

• I should use elimination because both equations are in standard form (example: 2X + 3Y = 10)

Choose the best method for solving this system of equations:

6X + 21Y = 44

-6X + 12Y = 14

• I should use elimination because both equations are in standard form (example: 2X + 3Y = 10)

• I should solve this system of equations using substitution because one of the equations tells me “X=____”, or “Y =____”

• I should solve this system of equations using graphing because both equations are in slope-intercept format (Y=MX+B).

How many solutions will this system have? 

• No solution
• One Solution
• I Don't Know
• Infinitely Many Solutions

What is the first step in solving a system of equations by elimination?

• Get both equations in standard form and line up the like terms.

• Get both equations in slope-intercept form.

• Get both equations equal to zero.

• Put the x terms first.

The solution (x, y) to a system of equations is the point where they...? 

• Run off the graph
• Don't touch
• Intersect
• Exist

3x + y = –14

–2x – y = 9

Which method would be best for solving this system?

• Substitution

• Elimination

• Graphing