Y=kx+m
{3=k*4+m
{15=k*6+m
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12=2k k=6 m=3-24=-21
ответ y=6x-21
Решение
x + y = 40
x*y = 364
y = 40 - x
x*(40 -x) = 364
x∧2 - 40x + 364 = 0
D = (40∧2 - 4*1*364 = 1600 - 1456 = 144
x1 = (40 - 12) / 2 = 14
x2 = (40 + 12) / 2 = 26
y1 = 40 - 14 = 26
y2 = 40 - 26 14
Ответ: (14; 26); (26;14)
=(3а^2-6а) -(а^2-6а+9) = 3а^2-6а-а^2+6а-9 = 2а^2-9
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