Помоги с 6,8,10,125.35

Question

Помоги с 6,8,10,125.35

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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