1.(a+b)(a-b)-(a-b) = (a-b)(a+b-1)
2.x^-4y^=0 = (x+2y)(x-2y)
3.6(535^-435^)=6(535+465)(535-465)=6*1000*70=420000
a²-a+b-b²
=(a-b)(a+b)-(a-b)
=(a-b)(a+b-1)
x(x-1)-2y(2y+1)
=x²-x-4y²-2y
=(x²-2²y²)-x-2y
=(x-2y)(x+2y)-(x+2y)
=(x+2y)(x-2y-1)
535²*6-6*465²
=6(535²-465²)
=6(535-465)(535+465)
=6(70)(1000)
=4.2*10^5
a^2-a+b-b^2
=(a^2-b^2)-a+b
=(a+b)(a-b)-(a-b)
=(a+b)(a-b)-(a-b)
=(a-b)(a+b-1)
x(x-1)-2y(2y+1)
=x^2-x-4y^2-2y
=(x^2-4y^2)-x-2y
=(x+2y)(x-2y)-(x+2y)
=(x+2y)(x-2y-1)
535^2x6-6x465^2
=6x(535^2-465^2)
=6x(535+465)(535-465)
=6x1000x70
=420x1000
=420000
1 (a-b)(a+b-1)
2 (x+2y)(x-2y-1)
3 420000