👉🏼 Factorise 7x^{2} + 8x + 1

👈🏼 Solve the following simultaneous equations:

y + 1 = 2x

y = x + 2

🖐🏼 Calculate

👆🏼 Every time a ball bounces, it rises to

80% of the previous height.

The ball is dropped from 5 metres and it

allows to bounce freely.

What is the smallest number of bounces until its rebound height is less than 50cm?

👇🏼 Solve x^{2} − 4x − 21 > 0