Question

15y²+7y-(13y-5y²)

2)2c*(a-3b+4)

3)(4x-1)(2x-3)

4)(a+2)(a²-a-3) 

Answer 1

$15y^2+7y-(13y-5y^2)=15y^2+7y-13y+5y^2=20y^2-6y;\ 2)2c*(a-3b+4)=2ac-6bc+8c;\ 3)(4x-1)(2x-3)=8x^2-2x-12x+3=8x^2-14x+3;\ 4)(a+2)(a^2-a-3) =a^3-a^2-3a+2a^2-2a-6=a^3+a^2-5a-6$