Secondary School (English Medium) (5 to 8) Class 8 - CBSE Question Bank Solutions for Mathematics

Factorise the following.

y² + 4y – 21

Factorise the following.

y² – 2y – 15

Factorise the following.

x² – 10x + 21

Factorise the following.

x² – 17x + 60

Factorise the following.

x² + 4x – 77

Factorise the following.

p² – 13p – 30

Factorise the following.

a² – 16p – 80

The curved surface area of a cylinder is 2π(y² – 7y + 12) and its radius is (y – 3). Find the height of the cylinder (C.S.A. of cylinder = 2πrh).

If x – y = 13 and xy = 28, then find x² + y².

If m – n = 16 and m² + n² = 400, then find mn.

Verify the following:

(a – b)(a – b)(a – b) = a³ – 3a²b + 3ab² – b³ 

Subtract b(b² + b – 7) + 5 from 3b² – 8 and find the value of expression obtained for b = – 3.

If `x - 1/x = 7` then find the value of `x^2 + 1/x^2`.

If the diagonals of a quadrilateral bisect each other, it is a ______.

If diagonals of a quadrilateral bisect each other, it must be a parallelogram.

The point of intersection of diagonals of a quadrilateral divides one diagonal in the ratio 1:2. Can it be a parallelogram? Why or why not?

Two sticks each of length 5 cm are crossing each other such that they bisect each other. What shape is formed by joining their endpoints? Give reason.

Two sticks each of length 7 cm are crossing each other such that they bisect each other at right angles. What shape is formed by joining their end points? Give reason.

a² – b² = (a + b) ______.