3t^2 + 7t + 4 = 0
D = 49 - 4*4*3 = 1
t1 = ( - 7 +1)/6 = - 6/6 = - 1;
t2 = ( - 7 - 1)/6 = - 4/3 = - 1 целая 1/3
У(-2)= - 2*2-6*(-2)-13=-4-12-13=-29
У(7)=7*2-6*7-13=14-42-13=-41
D=100-84=16 x1=-10+4/6=1. X2=-10-4/6=-7/3
Обозначим второе число через x , тогда :
![\frac{5\frac{1}{5}+x} {2}=4,4\\\\\frac{5,2+x}{2}=4,4\\\\5,2+x=8,8\\\\x=8,8-5,2\\\\x=3,6](https://tex.z-dn.net/?f=%5Cfrac%7B5%5Cfrac%7B1%7D%7B5%7D%2Bx%7D+%7B2%7D%3D4%2C4%5C%5C%5C%5C%5Cfrac%7B5%2C2%2Bx%7D%7B2%7D%3D4%2C4%5C%5C%5C%5C5%2C2%2Bx%3D8%2C8%5C%5C%5C%5Cx%3D8%2C8-5%2C2%5C%5C%5C%5Cx%3D3%2C6)
Ответ : 3,6