Steps to Solve System of Equations

• (1, 4)

• (4, 1)

• (1, -4)

• (-4, 1)

To solve the system, what should the top equation be multiplied by?

3x - y = 4

2x - 3y = -9

To solve the system, what should the top equation be multiplied by?

x + y = 2

-3x + 4y = 15

Solve the system

y = -x - 4

y = x - 2

• ( -1, -3 )

• No solution

• Infinitely many solutions

• ( 1, 3 )

Solve the system

-4x + 9y = 9

x = 3y - 6

• ( 5, 9 )

• ( -9 , -5 )

• x = 9

• ( 9 , 5 )

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

This was our original system and 2x-3y=-11 and 2x+y=9 We solved the second equation for y to get the system 2x-3y=-11, y=9-2x We plug the second equation into the first and solve to get x=2. Now, plug x=2 into any equation to solve for y. y=_____

Solve the system of equations using substitution:
x = -1
y = 3x + 2

• (1, 1)

• (2, -1)

• (-1, -1)

• (-1, 2)

Which variable should you isolate first in the system?

• The x in the first equation

• The y in the first equation

• The y in the second equation

• The x in the second equation

Use the system of equations below to answer the question. After substituting the first equation into the second one and working it out, I got x = 1. What should I do next? y = 6x 2x + 5y = 32

• Fill in 1 for x in y = 6x

• Fill in 1 for y in y = 6x

• Fill in 1 for y in 2x + 5y = 32