1. -8=18x-5x²
2. x²+25=10x

1. -8=18х-5х²5х²-18х-8=0D=324+4*5*8=√484x1=18+22/2*5=40/10=4x2=18-22/2*5=-4/10=-2/5=-0,42. x²+25=10xx²-10x+25=0D=100-4*25=0; D=0 один кореньх=-b/2a=10/2=5