a) 4x-10-4x^2+9=0

-4x^2+4x-1=0 |*(-1)

4x^2-4x+1=0

Д= -b^2-4ac=16-16=0

x=-b/2a

x=4/8=1/2=0,5

^2=степень

б)9y^2-25=0

(3y-5)(3y+5)=0

4x^-20x+25-4x^-9=0

4x^-20x-4x^=0-25+9

-20x=-16

x=-16:(-20)

x=0,8

^=2 cтепень