tentukan hasil pemangkatan berikut ini a.(2a+3b+c)² b.(3a-2b+5c)² tolong jwb pake cara

(2a+3b+c)² = (2a+3b+c)+ (2a+3b+c)
= (4a² + 6ab + 2ac) + (6ab + 9b² + 3bc) + (2ac + 3bc + c²)
= 4a² + 9b² + c² + 12ab + 4ac + 6 bc

(3a-2b+5c)² = (3a-2b+5c) + (3a-2b+5c)
= (9a² + 6ab + (-15ac)) + ((-6ab) + 4b² +(-10bc)) + (15ac + (-10bc) + 25c²
= 9a²+4b²+25c²+(-20bc)

a.(2a+3b+c)^2
= (2a+3b+c) (2a+3b+c)
= 4a^2+6ab+2ac+6ab+9b^2+3bc
+2ca+3bc+c^2
= 4a^2+6ab+6ab+2ac+2ac+3bc+3bc
+9b^2+c^2
= 4a^2+12ab+4ac+6bc+9b^2+c^2
_______________________________
b.(3a-2b+5c)^2
= (3a-2b+5c) (3a-2b+5c)
= 9a^2-6ab+15ac-6ab+4b^2-10cb
+15ac-10cb+25c^2
= 9a^2-6ab-6ab+15ac+15ac-10cb
-10cb+4b^2+25c^2
= 9a^2-12ab+30ac-10cb+4b^2+25c^2
maaf kalau salah