A sequence is defined by a_n. The value of a₁ – a₃ is ____.

If the nth term of AP -2, 5, 12, … is 89, then value of n is

For what values of p does the pair of equations 4x + py + 8 = 0 and 2x + 2y + 2 = 0 has unique solution?

OR

What type of straight lines will be represented by the system of equations 2x + 3y = 5 and 4x + 6y = 7?

A hemispherical depression is taken out from a cube with the side ‘2a’. The total surface area of the solid is __________.

If one root of the quadratic equation 3x² – ax + 4 = 0 is 4. Find the value of a.