First Step Substitution Systems

Solve the following systems of equations using substitution:

• (6, 3)

• (1, 2)

• (3, 6)

• (2, 1)

Which answer has a correct first step for this system:

• The variable is already isolated, so we've already solved the system.

• The variable is already isolated for y, so we substitute it in the first equation and solve for x

  3x + 3(3x + 5) = 3

• Free sha vaca doo

• The variable is already isolated for y, so we substitute it in the second equation and solve for x

  y = 3(3x + 3y) = 3

Solve this system using substitution

y = 3x - 5

2x + 4y = -6

• (1, -2)

• (2, -2)

• (1, 2)

• Why have you done this?

Solve with substitution

x = -3y - 8

x - 2y = -3

• (5, -1)

• (-5, 1)

• (-5,-1)

• (1,-5)

Solve the following system by substitution.  What is the solution?

• (1, -2)

• (-2, 1)

• (-4, 1)

• (2, 1)

Solve the system by substitution

• (1,1)

• (-1,1)

• (-1,0)

• (1,-1)

What is the solution to this system? Solve by substitution.
y= 4x + 3
2x - 3y = 21

• (3,-9)

• (-3,-9)

• (-3,9)

• (0,1)

Solve this system by substitution.

• (1, -4)

• (1, 4)

• (-4, -7)

• (-7, -4)

Solve the system of equations.

• (-6, 30)

• (-2, 10)

• (44, 39)

• No solution

• Infinite solutions

Solve the system of equations.