y²-15y+56=0,then y=?

A -5 and 6

B -7 and 8

C 6 and 9

D 7 and 8

Correct Answer: Option D

দেওয়া আছে ,
y²-15y+56=0
বা, y²-8y-7y+56 =0
বা, y(y-8)-7(y-8)=0
∴ (y-8)(Y-7)=0
অতএব, y=7,8