First Step Systems Substitution

Solve the following systems of equations using substitution:

5x - 2y = 3

y = 2x

• (6, 3)

• (1, 2)

• (3, 6)

• (2, 1)

Solve the system of equations.

• (-6, 1)

• (-12, -12)

• (1, -6)

• No solution

• Infinite solutions

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 the system by substitution

• (1,1)

• (-1,1)

• (-1,0)

• (1,-1)

Solve this system by substitution.

• (1, -4)

• (1, 4)

• (-4, -7)

• (-7, -4)

Solve the system of linear equations by substitution.

5x + 2y = 9

x + y = -3

​ ​ ​ (a)   ​ (b)  

• y = -22

• x = -3

• x = 1

• y = -4

• x = 5

• y = -8

• x = -8

• y = 4

The solution to the system of equations y = 2x + 1 and y = 4x - 1 is (a)   .

• (1,3)

• (0,0)

• (2,5)

• (3,7)

Solve the system of linear equations by substitution.

-5x + 3y = 51

y = 10x - 8​

​ ​ ​ (a)   ​ (b)  

• y = -22

• x = -3

• x = 59/25

• y = 15.6

• x = 3

• y = 22

• x = -8

• y = 4

solve by substitution: y=3x+14
y=-4x

• y=3

• y=1

• y= - 2

• y=4