✨ ベストアンサー ✨
(2a+10)^2-100
=4a^2 +40a+100-100
=4a^2 +40a
=4a(a+10)
(x+3)^2 -(y-3)^2
=x^2 +6x+9-y^2 +6y-9
=x^2 +6x-y^2 +6y
=(x^2 -y^2)+6(x+y)
=(x+y)(x-y)+6(x+y)
=(x+y)(x-y+6)
✨ ベストアンサー ✨
(2a+10)^2-100
=4a^2 +40a+100-100
=4a^2 +40a
=4a(a+10)
(x+3)^2 -(y-3)^2
=x^2 +6x+9-y^2 +6y-9
=x^2 +6x-y^2 +6y
=(x^2 -y^2)+6(x+y)
=(x+y)(x-y)+6(x+y)
=(x+y)(x-y+6)
ありがとうございます🙇🏻✨