Question

5x²-3(y+1) (y-1)

Answer 1

5x²-3(y+1) (y-1)=5x²-3(y²-1)=5x²-3y²+3

 

ze wzoru skr mnoz

 

(a-b)(a+b)=a²-b²

(y+1) (y-1)=y²-1

Answer 2

5x²-3(y+1) (y-1) = 5x²-3(y²-1²) = 5x²-3(y²-1)=5x²-3y²+3