I can't understand this. I just don't get it

What is the nth term rule of the linear sequence below? 27 , 25 , 23 , 21 , 19 , . .

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

Me! i will mark you brainliest if you are right and show your i don't get polynomials and all the other stuff. multiply and simplify.2x(^2)y(^3)z(^2) · 4xy(^4)x(^2)show your