25 x2 x 9 0. 4x2+6x+9=0. X-2/6-X/2=2. X2-6x+9. -(5x-2)+(2 5x2-3 2x+5=-3. X2-3x-1-2x2+3x-5/2 1.5. 3x+(2x-1)=10. X^2+X^3+X^3+X^4=. X2+25/x. 2/5x+5/9x. (X+4)^2=(X-5)^2. 4x 2-8x+3/4x 2-1. X2+18x+81. (X-9):x2-18x+81/x+9. Система x2 + y2 =25 XY = 25. X2+y=25 x2-y=7 уравнение