Запиши уравнение, равносильное данному: 4x+3=27; 5-x=4-x; (X2):X = 0; x(+2):x=0

x^2-8x+17=0 => D=64-4*17 = Р Н 

4x=-49-x^2 => x^2+4x+49=0 => D=16-4*49=Р Н

36+17x=2x^2 => 2x^2+17x+36=0 =>D=289-288=1 => x1=-9/2 => x2=-4

7x^2-3x=4 = > D9-4*7*(-4)=121 => x1=1 => x2=-9/14

x^2=81 = > x=+-9

5x+9x^2=0 => x(5+9x)=0 =>x=0 или x=-5/9

1+2x=8x^2 => 8x^2-2x-1=0 => D=4-4*8*(-1)=36 => x1=1/2 => x2=-1/4

19x-6x^2-10=0 =>6x^2-19x+10=0 =>D=361-4*6*10=121 =>x1=30/38 => x2=8/38

8+2x^2=0 => 2x^2=-8 => x^2=-4 => x=Р Н

40x-25x^2+12x=0 => 28-25x^2=0 =>x(28-25x)=0 => x=0 или 25x=28 => x=28/25