ZAD.2.
(4+2x)(8+2x)=45+32
32+8x+16x+4x^2=77
4x^2+24x=77-32
4x^2+24x-45=0
\Delta=b^2-4ac=24^2-4*4*(-45)=576+720=1296
\sqrt{\Delta}=36
x_1=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-24-36}{8}=-7,5(odrzucamy)
x_2=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-24+36}{8}=1,5
ZAD.3.
(12+x)(18+2x)=12 \cdot 18+144
216+24x+18x+2x^2=216+144
2x^2+42x=360-216
2x^2+42x-144=0
równanie kwadratowe
…
x_1=-24
x_2= 3