Решите уравнение : 7y^2-11y+4=0

7у²-11у+4=0

Д = 121-4*7*4 = 121 - 7*16 = 121-112 = 9 = 3²

у(1) = (11+3) / 14 = 14/14=1

у(2) = (11-3) / 14 = 8/14=4/7

7y²-11y+4=0D=b²-4ac=121-4×7×4=121-112=9√D=√9=3y(1)= (-b+√D)/2a=(11+3)/2×7=(14)/14=1y(2)=(-b-√D)/2a=(11-3)/14=(8)/14=4/7