20. What is the slope of the line that passes through (-6, -4) and (9, -19)?

Factorize: x^2+8x+10 i just solved it but i don't know if the process is correct

Astick 2 m long is placed vertically at point b. the top of the stick is in line with the top of a tree as seen from point a, which is 3 m from the stick and 30 m from the tree. how tall is the tree?

The distance of a chord from the centre of a circle is 12cm and the lenght of the chord is 10cm. find the radius of the circle