Если сторона 2x то другая 3x такак отношения 3/2площадь 2x*3x=6x^2после увеличения площадь (2x+1)(3x+1)(2x+1)(3x+1)-6x^2=3^26x^2+3x+2x+1-6x^2=95x=8x=8/52x=16/53x=24/5(24/5+1)(16/5+1)-16/5*24/5=24/5*16/5+24/5+16/5+1-16/5*24/5=24/5+16/5+1=9=3^2
3. Найдите A ∪ B, B ∩ C, A \ B, B \ C, ( A ∪ B ) ∩ C, если: 5) A = Z, B = { 12, 14, 16, 24 }, C = N.
Анюта66666 [851]
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5 минус 2 корня из 5 плюс 1 разделить все это на 4
2.
![\frac{(x+y)^{2}-(x-y)^{2}}{x^{2} -y^{2} }* \frac{x^{2} -y^{2} }{xy} = \frac{(x+y-x+y)(x+y+x-y)}{xy}= \frac{2x*2y}{xy}=4](https://tex.z-dn.net/?f=+%5Cfrac%7B%28x%2By%29%5E%7B2%7D-%28x-y%29%5E%7B2%7D%7D%7Bx%5E%7B2%7D+-y%5E%7B2%7D+%7D%2A++%5Cfrac%7Bx%5E%7B2%7D+-y%5E%7B2%7D+%7D%7Bxy%7D+%3D+%5Cfrac%7B%28x%2By-x%2By%29%28x%2By%2Bx-y%29%7D%7Bxy%7D%3D+%5Cfrac%7B2x%2A2y%7D%7Bxy%7D%3D4++)
3.
![\frac{c^{2} }{(c-5)^{2}}* \frac{-1(c+5)(c-5)}{5(c+5)}+ \frac{c}{c-5}= \frac{-c^{2}+5c}{5(c-5)} = \frac{-c(c-5)}{5(c-5)}=- \frac{c}{5}](https://tex.z-dn.net/?f=%5Cfrac%7Bc%5E%7B2%7D+%7D%7B%28c-5%29%5E%7B2%7D%7D%2A+%5Cfrac%7B-1%28c%2B5%29%28c-5%29%7D%7B5%28c%2B5%29%7D%2B+%5Cfrac%7Bc%7D%7Bc-5%7D%3D+%5Cfrac%7B-c%5E%7B2%7D%2B5c%7D%7B5%28c-5%29%7D+%3D+%5Cfrac%7B-c%28c-5%29%7D%7B5%28c-5%29%7D%3D-+%5Cfrac%7Bc%7D%7B5%7D)
4. ОДЗ: x≠0 и x≠3
![\frac{x}{3-x}= \frac{6}{x}-1](https://tex.z-dn.net/?f=+%5Cfrac%7Bx%7D%7B3-x%7D%3D+%5Cfrac%7B6%7D%7Bx%7D-1++)
![\frac{x}{3-x}= \frac{6-x}{x}](https://tex.z-dn.net/?f=+%5Cfrac%7Bx%7D%7B3-x%7D%3D+%5Cfrac%7B6-x%7D%7Bx%7D++)
x²=18-3x-6x+x² ⇒ 9x=18 ⇒ x=2