№1
а) = 8(25y^2+30y+9)+9(9y^2-6y+1) = 200y^2+240y+56+81y^2-54y+9 = 281y^2+186y+65
б) = 7(4x^2-20x+25)+49x^2-14x+1 = 28x^2-140x+175+49x^2-14x+1 = 77x^2-154x+176
№2
а) = 16y^4+24y^2+9+81-56y^2+16y^4-2(16y^4+12y^2-36y^2-27) = 32y^4-32y^2+90-32y^4+48y^2+54 = 4y^2+144
№3
a) = x^2-9b^2-(x^3-2bx^2+4b2x+2bx^2-4b^2x+8b^3) = x^2-9b^2-x^3-8b^3 = x^2(1-x)-b^2(9+8b)