Упростите выражения:

1) (x+2) (x-5) - 3x (1-2x)

2) (a+3) (a-2) + (a-3) (a+6)

3) (x-7) (3x-2) - (5x+1) (2x-4)

4) (5x-2y) (3x+5y) - (2,5x-3y) (4x+8y)

5) (3a²+5y) (2a³+y) - 7a³ (a²-3y)

Упростите выражения:

1) (x+2) (x-5) - 3x (1-2x)

x^2-5x+2x-10-3x+6x^2=7x^2-6x-10

2) (a+3) (a-2) + (a-3) (a+6)

a^2-2a+3a-6+a^2+6a-3a-18=

2a^2+4a-24=a^2+2a-12

3) (x-7) (3x-2) - (5x+1) (2x-4)

3x^2-2x-21x+14 - (10x^2-20x+2x-4) =

3x^2-23x+14-10x^2+18x-4=

-7x^2-5x+10

4) (5x-2y) (3x+5y) - (2,5x-3y) (4x+8y)

15x^2+25xy-6xy-10y^2 - (10x^2+20xy-12xy-24y^2) =

15x^2+19xy-10y^2-10x^2-8xy+24y^2=

5x^2+14y^2+11xy

5) (3a²+5y) (2a³+y) - 7a³ (a²-3y)

6a^5+3a^2y+10a^3y+5y^2-7a^5+21a^3y=

-a^5+3a^2y+31a^3y+5y^2