Which of the following are linear equations?

1.   ?    xy + 6 = 2
2.   ?    x³ + 4 = 1 + y
3.   ?    3x/y + 2 = 0
4.   ?    √x = y + 2

At what value of y does 4x – 3y = 8 cut the y-axis?

1.   ?    -8/3
2.   ?    8/3
3.   ?    -3/4
4.   ?    -3/8

(1,2) and which other point lie on a straight line which intersects the y-axis at y = -1

1.   ?    (4,11)
2.   ?    (2,6)
3.   ?    (6,15)
4.   ?    (-2,-5)

What is the gradient of the line 3x – 7y = 14?

1.   ?    -2
2.   ?    7/3
3.   ?    3/7
4.   ?    -1/2

Which of the following lines has a gradient of – 2/3?

1.   ?    6x – 2 = 3y
2.   ?    -15y – 5 = 10x
3.   ?    8 – 2y = 3x
4.   ?    -x + 3 = 2y

Complete the following sentence. Parallel lines have:

1.   ?    the same gradient and same point of intersection with the y-axis
2.   ?    different gradients but the same point of intersection with the y-axis
3.   ?    different gradients and a different point of intersection with the y-axis
4.   ?    the same gradient but a different point of intersection with the y-axis

Solve the following pair of linear equations; 3x + y = 8, 4x – 2y = 4

1.   ?    x = 3, y = -1
2.   ?    x = 2, y = 2
3.   ?    x = 1, y = 0
4.   ?    x = 2, y = -2

Solve the following pair of linear equations; x – 2y = 6, 3x – 4 = 6y

1.   ?    No solution
2.   ?    Many solutions
3.   ?    x = 2, y = 0
4.   ?    x = 4, y = -1

Solve the following pair of linear equations; 8x + 6y = 12, y = - 4x/3 +2

1.   ?    x = 3, y = 2
2.   ?    x = 4, y = -2/3
3.   ?    Many solutions
4.   ?    No solution

If the supply equation is P = 10 + 0.5Q and the demand equation is Q = 200 – 2P, what is the equilibrium price and quantity?

1.   ?    P = 45, Q = 70
2.   ?    P = 75, Q = 130
3.   ?    P = 35, Q = 50
4.   ?    P = 55, Q = 90