Упростите выражения 9x^2-(5x-1)(2x+3)

9x^2 - ( 5x - 1 )( 2x + 3 ) = 9x^2 - ( 10x^2 + 15x - 2x - 3 ) = 9x^2 - ( 10x^2 + 13x - 3 ) = 9x^2 - 10x^2 - 13x + 3 = - x^2 - 13x + 3

9x•2-(5x-1)(2x+3) 1)(5x-1)(2x+3)=5x•(2x+3)-1•(2x+3)=10x2+15x-2x-3=10x2+13x-3 2) 9x•2=18x 3) 18x-(10x2+13x-3)=18x-10x2-13x+3=5x-10x2+3