36y
2
−5y+c=
a
(6y)
−
2ab
5y
+
b
c
=
[a=6y,2ab=5y⇒2⋅6y⋅b=5y,12y⋅b=5y,b=
12
5
]
=(6y)
−2⋅6y⋅
+(
)
144
25
=(6y−
,
c=
36y
2
−5y+c=
a
2
(6y)
2
−
2ab
5y
+
b
2
c
=
[a=6y,2ab=5y⇒2⋅6y⋅b=5y,12y⋅b=5y,b=
12
5
]
=(6y)
2
−2⋅6y⋅
12
5
+(
12
5
)
2
=(6y)
2
−2⋅6y⋅
12
5
+
144
25
=(6y−
12
5
)
2
,
c=
144
25