i 4 2 minus 21 20 0 ii 3y 2 minus 19y 30 0 ........

Explanation:

(i) 4??^2 − 21?? + 20 = 0
4??^2 − 16?? − 5?? + 20 = 0
4??(?? − 4) − 5(?? − 4) = 0
(4?? − 5)(?? − 4) = 0
?? = 5/4 , 4
(ii) 3??^2 − 19?? + 30 = 0
3??^2 – 9?? − 10?? + 30 = 0
3??(?? − 3) − 10(?? − 3) = 0
(3?? − 10)(?? − 3) = 0
?? = 10/3 , 3
No relation exists