i

[tex]а) 4y^2=12,25 \\

y^2=3,0625 \\

y=\pm1,75 \\ \\

b) l^2+2l-8=0 \\

D=4+4\cdot8=36 \\

l_{1,2}=\dfrac{-2\pm6}{2}=-1\pm3=(2;-4) \\ \\

c) 9y^2+18y+5=p \\

D=18^2-4\cdot5\cdot9=144 \\

y_{1,2}=\dfrac{-18\pm12}{18}=(\dfrac{-1}{3};,\dfrac{-5}{3})[/tex]

[tex](z-2)^2+2z=7(z-2) \\

z^2-2z+4=7z-14 \\

z^2-9z+18=0 \\

D=81-4\cdot18=9 \\

z_{1,2}=\dfrac{9\pm3}{2}=(6; 3) \\

z_1+z_2=6+3=9[/tex]