Question

помоги с 6,8,10,12
5.35

Answer 1

6)(y-5)(y+5)=y^2-25

7)(1-a)(1+a)=1-a^2

10)(2x-3y)(2x+3y)=4x^2-9y^2

12)(5x+3y)(3y-5x)=15xy-25x^2+9y^2-15xy=9y^2-25x^2