(2a-5b)²-(2a+5b)²
x(x-2)-(x-3)²
y(3y-2)²-9y(4+y)²
(x+4)²-(x-2)(x+2)

ПЖ!!!!!!

(2a-5b)²-(2a+5b)²= (2a-5b-2a-5b)(2a-5b+2a+5b)= -10b*4a= -40ab

x(x-2)-(x-3)²= x²-2x-x²+6x-9= 4x-9

y(3y-2)²-9y(4+y)²= y(9y²-12y+4)-9y(16+8y+y²)= 9y³-12y²+4y-144y-72y²-9y³= -84y²-140y

(x+4)²-(x-2)(x+2)= x²+8x+16-x²+4= 8x+20

4a^2+25b^2-20ab-4a^2-20ab-25b^2=-40abx^2-2x-x^2+6x-9=4x-9y(9y^2-12y+4)-9y(16+y^2+8y)=9y^3-12y^2+4y-72y^2-9y^3-144y=-84y^2-140yx^2+8x+16-x^2+4=8x+20