What value should come in place of the question mark (?) in the following question?

52x14+145018=1998÷?

Find the sum of the measures all the exterior angles of a decagon.

Find equation of the perpendicular to segment joining the points A(0,4) and B(-5,9) and passing through the point P. Point P divides segment AB in the ratio 2:3.

If a cone of radius 10.5 cm and height 12 cm is melted and constructed into a cylinder of the same radius, what will be the height of this cylinder?

If cosecA - cotA = x, then the value of x is

If (1 - cosA)/2 = x, then the value of x is

If cos 60° - sec 30° = x, then the value of x is

The value of tan80° tan10° + sin270° + sin20∘

The amount of Rs. 10,000 after 2 years, compounded annually with the rate of interest being 10% per annum during the first year and 12% per annum during the second year, would be (in rupees)