5x10?+ 4x10°+ 3x10?+1
Answers
Explanation:
(2x−5y)
3
−(2x+5y)
3
=−250y
3
−120x
2
y
Step-by-step explanation:
Given : Expression (2x-5y)^3-(2x+5y)^3(2x−5y)
3
−(2x+5y)
3
To find : Simplify the expression?
Solution :
Using cubic identity,
(a-b)^3=a^3+b^3-3ab(a-b)(a−b)
3
=a
3
+b
3
−3ab(a−b)
Applying identity in (2x-5y)^3(2x−5y)
3
(2x-5y)^3=(2x)^3-(5y)^3-3(2x)(5y)(2x-5y)(2x−5y)
3
=(2x)
3
−(5y)
3
−3(2x)(5y)(2x−5y)
Applying identity in (2x+5y)^3(2x+5y)
3
(2x+5y)^3=(2x)^3+(5y)^3+3(2x)(5y)(2x+5y)(2x+5y)
3
=(2x)
3
+(5y)
3
+3(2x)(5y)(2x+5y)
Substitute in expression,
(2x-5y)^3-(2x+5y)^3(2x−5y)
3
−(2x+5y)
3
=(2x)^3-(5y)^3-3(2x)(5y)(2x-5y)-(2x)^3-(5y)^3-3(2x)(5y)(2x+5y)=(2x)
3
−(5y)
3
−3(2x)(5y)(2x−5y)−(2x)
3
−(5y)
3
−3(2x)(5y)(2x+5y)
=-125y^3-30xy(2x-5y)-125y^3-30xy(2x+5y)=−125y
3
−30xy(2x−5y)−125y
3
−30xy(2x+5y)
=-250y^3-60x^2y+150xy^2-60x^2y-150xy^2=−250y
3
−60x
2
y+150xy
2
−60x
2
y−150xy
2
=-250y^3-120x^2y=−250y
3
−120x
2
y
Therefore, (2x-5y)^3-(2x+5y)^3=-250y^3-120x^2y(2x−5y)
3
−(2x+5y)
3
=−250y
3
−120x
2
y