Simplify: (5a+3b)^3 -(5a-3b)^3 Please answer fast!!
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(x+y)^3-(x-y)^3
=[x+y-(x-y)][(x+y)^2+(x+y)(x-y)+(x-y)^2]
=2y[2x^2+2y^2+x^2-y^2]
=2y*(3x^2+y2)
=6x^2y+2y3-----(1)
here
x=5a, y=3b
(5a+3b)3-(5a-3b)^3
=6*(5a)^2*3b + 2*(3b)^3{from (1)}
=450a^2b+54b^3
=[x+y-(x-y)][(x+y)^2+(x+y)(x-y)+(x-y)^2]
=2y[2x^2+2y^2+x^2-y^2]
=2y*(3x^2+y2)
=6x^2y+2y3-----(1)
here
x=5a, y=3b
(5a+3b)3-(5a-3b)^3
=6*(5a)^2*3b + 2*(3b)^3{from (1)}
=450a^2b+54b^3
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