<span>9x^2-10a^3+6ax-15a^2x = (</span><span>9x^2+6ax) - (15a^2x</span><span>+10a^3) = 3х(3х+2а) - 5</span><span>a^2(</span>3х+2а) = (3х+2а)*(3х-5a^2)
(2a-b)^3-(2a+b)^3 = 8a^3-12a^2b+6ab^2-<span>b^3 - </span> 8a^3-12a^2b-6ab^2-b^3 = -24a^2b - 2b^3 = -2b*(12a^2+<span>b^</span>2)
( 2x+ 5)(3x - 7) + (2x - 1)(2x + 1) = (5x + 3)(2x - 5)
6x^2 + x - 35 + 4x^2 - 1 = 10x^2 - 19x - 15
10x^2 + x - 36 = 10x^2 - 19x - 15
10x^2 - 10x^2 + x + 19x = - 15 + 36
20x = 21
x = 21/20
x = 1,05
6-10y=7,3-12y-4; -10y+12y=3,3-6; 2y= -2,7 ; y=(-2,7):2= -1,35. Ответ: y= -1,35.