Ответ:

Объяснение:

a) ((2x-5)²+(3x+4)²)² =(4x²-20x+25+9x²+24x+16)² =(13x²+4x+41)²= =169x⁴+16x²+1681+104x³+1066x²+328x= =169x⁴+104x³+1082x²+328x+1681

b) ((x+2y)² +(5x-6y)²)²=  (x²+4xy+4y²+25x²-60xy+36y²)²=(26x²-56xy+40y²)²=

= (676x⁴ +3136x²y²+1600y⁴-2912x³y+2080x²y²-4480xy³=

=676x⁴+5216x²y²+1600y⁴-2912x³y-4480xy³

c) ((6-8x)²-(9x-4)²)² =(36-96x+64x² -(81x²-72x+16))² =(36-96x+64x² -81x²+72x-16)²  =(20-24x-17x²)² =400+576x²+289x⁴-960x-680x²+816x³=

=289x⁴+816x³-104x²-960x+400

d)  ((3x+7y)²- (4x-5y)²)²= (9x²+42xy+49y²-16x²+40xy-25y²)² =

=(24y²-7x²+82xy)² =575y⁴+49x⁴+6724x²y²-336y²x² -1148x³y+3936y³=

=575y⁴+49x⁴+6388x²y²-1148x³y+3936y³