Преобразуйте в многочлен (3x-4y)^2-(2x-7y)(4x+2y) 2x(2x+3)^2-(2x-3)(4x^2+6x=9)

9х^2-24xy+16y^2-(8x^2+4xy-28xy-14y^2)=9х^2-24xy+16y^2-8x^2-4xy+28xy+14y^2= =x^2+30y^2 2x(2x+3)^2-(2x-3)(4x^2+6x+9)=2x(4x^2+12x+9)-(8x^3+12x^2+18x-12x^2-18x-27)= =8x^3+24x^2+18x-8x^3-12x^2-18x+12x^2+18x+27=24x^2+18x+27=3(8x^2+6x+9)