Ответ:всего 9 целых чисел принадлежит этому промежутку
(a-b)(a+b)=a²-b²
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(9x-3)(9x+3)-81x²-7x+9=81x²-9-81x²-7x+9=-7x
x=140 -7*140=-980
log(1/11) (3^(1 + log(33) x) - 1/11^(1 + log(33) x ) ) ≥ 1 + log(33) x
одз x>0
3^(1 + log(33) x) - 1/11^(1 + log(33) x ) > 0
3^(1 + log(33) x) *11^(1 + log(33) x > 1
33^(1 + log(33) x) > 33^0
1 + log(33) x > 0
x > 1/33
log(1/11) (3^(1 + log(33) x) - 1/11^(1 + log(33) x ) ) ≥ 1 + log(33) x
log(1/11) (3^(1 + log(33) x) - 1/11^(1 + log(33) x ) ) ≥ log(1/11) 1/11^(1 + log(33) x)
3^(1 + log(33) x) - 1/11^(1 + log(33) x ) ≤ 1/11^(1 + log(33) x
3^(1 + log(33) x) - 2/11^(1 + log(33) x ) ≤ 0
(3^(1 + log(33) x)*11(1 + log(33) x) - 2)/11^(1 + log(33) x ) ≤ 0
3^(1 + log(33) x)*11(1 + log(33) x) - 2 ≤ 0
33^(1 + log(33) x) ≤ 2
{ a^log(a) b = b a^(m+n) = a^m*a^n}
33 * x ≤ 2
x≤ 2/33
пересекаем с одз
x∈(1/33 2/33]
5x<span>²+8x-4=0
D=8</span>²-4*5*(-4)=64+80=144=12<span>²
x1=-8+12\2*5=4\10=0,4
x2=-8-12\2*5=-20\10=-2
х1+х2=0,4+(-2)=0,4-2=-1,6
Ответ: -1,6</span>