31.
The graph of 3x + 4y - 24 = 0 forms a triangle OAB with the co-ordinate axes, where O is the origin. Also the graph of x + y + 4 = 0 forms a triangle OCD with the coordinate axes. Then the area of ΔOCD is equal to:

32.
The distance between the points (4, 8) and (k, -4) is 13. What is the value of k?

33.
The slope of the line passing through the points (2, -1) and (x, 5) is -1. Find x?

34.
For what value of m will the system of equations 17x + my + 102 = 0 and 23x + 299y + 138 = 0 have infinite number of solutions?

35.
For what value of k, the system of equations kx + 2y = 2 and 3x + y = 1 will be coincident?

36.
The area (in sq. units) of the triangle formed by the graphs of 8x + 3y = 24, 2x + 8 = y and the x-axis is:

37.
The line passing through (-3, 4) and (0, 3) is perpendicular to the line passing through (5, 7) and (4, x). What is the value of x?

38.
If (2, 0) is a solution of the linear equation 2x + 3y = 5, then the value of k is:

39.
What is the y-intercept of the linear equation 59x + 14y - 112 = 0?

40.
The graphs of the equations 2x + 3y = 11 and x - 2y + 12 = 0 intersects at P(x1, y1) and the graph of the equation x - 2y + 12 = 0 intersects the x-axis at Q(x2, y2). What is the value of (x1 - x2 + y1 + y2)?