1) 2y(6x +¹/₄y)² - x(8x+3y)² =
=2y(36x² +3xy+¹/₁₆ y²) - x(64x²+48xy+9y²)=
=72x²y+6xy² +¹/₈ y³ - 64x³ -48x²y -9xy²=
=¹/₈ y³ - 3xy² +24x²y -64x³ =
=(¹/₂ y)³ - 3*(¹/₂ y)² *4x + 3* ¹/₂ y *(4x)² - (4x)³ =
=(¹/₂ y -4x)³
2) y⁶ - 4y⁴ +7y³ -6y²+10 - (5+2y²) =
y³ -2y²+2
=y⁶ -4y⁴ +7y³ -6y² +10 -(5+2y²)(y³ -2y² +2) =
y³ -2y² +2
=y⁶ -4y⁴ +7y³ -6y² +10 -(5y³+2y⁵-10y²-4y⁴+10+4y²)=
y³ -2y² +2
=y⁶ -4y⁴ +7y³ -6y² +10 -5y³ -2y⁵ +6y² +4y⁴ -10 =
y³ -2y² +2
= y⁶ -2y⁵ +2y³ =
y³ -2y² +2
=y³ (y³ -2y² +2) = y³
y³ -2y² +2