Question

Даю 60 баллов срочно!!!

Answer 1

Ответ:

$1)\ \ y=-\dfrac{1}{4}\\\\-y(y-4)+(y+7)(y-7)=-y^2+4y+y^2-49=4y-49=\\\\=4\cdot \Big(-\dfrac{1}{4}\Big)-49=-1-49=-50\\\\\\2)\ \ A(3\frac{13}{18})\ \ ,\ \ B(-4\frac{2}{21})\ \ ,\ \ C(3,87)\\\\3\frac{13}{18}\approx 3,72<3,87\ \ ,\ \ -4\frac{2}{21}\approx -4,095\approx-4,10$