solving by substitution

what is the form of the answer to a system of equations whose lines cross once?

• (x, y)

• no solution

• (y, x)

• infinite solutions

what is the form of the answer to a system of equations whose lines do not cross?

• (x, y)

• no solution

• (y, x)

• infinite solutions

what is the form of the answer to a system of equations whose lines are the same?

• (x, y)

• no solution

• (y, x)

• infinite solutions

solve the system:

y = 2x

3x + 3y = 27

• (-3, -9)

• (3, 6)

• (-3, -6)

• (3, 9)

solve the system:

y = 4x

2x - 3y = -50

• (-3, -12)

• (4, 16)

• (5, 20)

• (5, 15)

solve the system:

y = 4

2x - 3y = -50

• (19, 4)

• (4, 19)

• (-4, 19)

• (-19, 4)

consider the system:

y = 4x

2x - 3y = -50

based on the equations given, which variable would we solve for first?

• x

• y

• not enough information to say

consider the system:

x = 3y

2x + 3y = 36

what would the second equation look like after substitution?

• 3y + 3y = 36

• 23y + 3y = 36

• 2x + 3y = 3y

• 2(3y) + 3y = 36

solve the system:

x = 3y

2x + 3y = 36

• (-4, 12)

• (12, 4)

• no solution

• (4, 12)

solve the system:

x = 3

2x - 5y = -14

• (4, 3)

• (2, 3)

• (3, 4)

• (3, 3)