<span>Воспользуемся формулой суммы тангенсов:</span>
<span>tg(x/3 + pi/4)+tg(x/3 - pi/4)=sin(2x/3)/(cos(x/3+pi/4)*cos(x/3-pi/4)=</span>
<span>sin(2x/3)/(0.5(cos(pi/2)+cos(2x/3))=2tg(2x/3)</span>
X=-2/5
x=2/5
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101² = (100+1)² = 100² + 2*1*100 + 1² = 10 000 + 200 + 1 = 10 201
48² = (50-2)² = 50² - 2 * 50 * 2 + (-2)² = 2 500 - 200 + 4 = 2 304
(4-5x)(4+5x)
-(2x^2+y^2)(2x^2-y^2)