![\frac{a-5}{6-3a} + \frac{4(a+1)}{a^{2}+4a} : (\frac{9a}{a^{2}-16} - \frac{a+4}{a^{2}-4a}) = \frac{a-5}{6-3a} + \frac{4(a+1)}{a^{2}+4a} : (\frac{9a}{(a-4)(a+4)} - \frac{a+4}{a(a-4)}) = \frac{a-5}{6-3a} + \frac{4(a+1)}{a^{2}+4a} : (\frac{9a*a -(a+4)^2}{a(a-4)(a+4)}) = \frac{a-5}{6-3a} + \frac{4(a+1)}{a^{2}+4a} : (\frac{9a^2 -a^2-8a-16}{a(a-4)(a+4)}) = \frac{a-5}{6-3a} + \frac{4(a+1)}{a^{2}+4a} : (\frac{8a^2-8a-16}{a(a-4)(a+4)}) =](https://tex.z-dn.net/?f=+%5Cfrac%7Ba-5%7D%7B6-3a%7D+%2B+%5Cfrac%7B4%28a%2B1%29%7D%7Ba%5E%7B2%7D%2B4a%7D+%3A+%28%5Cfrac%7B9a%7D%7Ba%5E%7B2%7D-16%7D+-+%5Cfrac%7Ba%2B4%7D%7Ba%5E%7B2%7D-4a%7D%29+%3D+%5Cfrac%7Ba-5%7D%7B6-3a%7D+%2B+%5Cfrac%7B4%28a%2B1%29%7D%7Ba%5E%7B2%7D%2B4a%7D+%3A+%28%5Cfrac%7B9a%7D%7B%28a-4%29%28a%2B4%29%7D+-+%5Cfrac%7Ba%2B4%7D%7Ba%28a-4%29%7D%29+%3D+%5Cfrac%7Ba-5%7D%7B6-3a%7D+%2B+%5Cfrac%7B4%28a%2B1%29%7D%7Ba%5E%7B2%7D%2B4a%7D+%3A+%28%5Cfrac%7B9a%2Aa+-%28a%2B4%29%5E2%7D%7Ba%28a-4%29%28a%2B4%29%7D%29+%3D+%5Cfrac%7Ba-5%7D%7B6-3a%7D+%2B+%5Cfrac%7B4%28a%2B1%29%7D%7Ba%5E%7B2%7D%2B4a%7D+%3A+%28%5Cfrac%7B9a%5E2+-a%5E2-8a-16%7D%7Ba%28a-4%29%28a%2B4%29%7D%29+%3D+%5Cfrac%7Ba-5%7D%7B6-3a%7D+%2B+%5Cfrac%7B4%28a%2B1%29%7D%7Ba%5E%7B2%7D%2B4a%7D+%3A+%28%5Cfrac%7B8a%5E2-8a-16%7D%7Ba%28a-4%29%28a%2B4%29%7D%29+%3D+)
![\frac{a-5}{6-3a} + \frac{4(a+1)}{a^{2}+4a} :\frac{8(a^2-a-2)}{a(a-4)(a+4)} = \frac{a-5}{6-3a} + \frac{4(a+1)}{a^{2}+4a} : \frac{8(a-2)(a+1)}{a(a-4)(a+4)} = \frac{a-5}{6-3a} + \frac{4(a+1)}{a(a+4)} * \frac{a(a-4)(a+4)}{8(a-2)(a+1)}= \frac{a-5}{6-3a} + \frac{4(a+1)a(a-4)(a+4)}{a(a+4) *8(a-2)(a+1)}=](https://tex.z-dn.net/?f=+%5Cfrac%7Ba-5%7D%7B6-3a%7D+%2B+%5Cfrac%7B4%28a%2B1%29%7D%7Ba%5E%7B2%7D%2B4a%7D+%3A%5Cfrac%7B8%28a%5E2-a-2%29%7D%7Ba%28a-4%29%28a%2B4%29%7D+%3D+%5Cfrac%7Ba-5%7D%7B6-3a%7D+%2B+%5Cfrac%7B4%28a%2B1%29%7D%7Ba%5E%7B2%7D%2B4a%7D+%3A+%5Cfrac%7B8%28a-2%29%28a%2B1%29%7D%7Ba%28a-4%29%28a%2B4%29%7D+%3D+%5Cfrac%7Ba-5%7D%7B6-3a%7D+%2B+%5Cfrac%7B4%28a%2B1%29%7D%7Ba%28a%2B4%29%7D+%2A+%5Cfrac%7Ba%28a-4%29%28a%2B4%29%7D%7B8%28a-2%29%28a%2B1%29%7D%3D+%5Cfrac%7Ba-5%7D%7B6-3a%7D+%2B+%5Cfrac%7B4%28a%2B1%29a%28a-4%29%28a%2B4%29%7D%7Ba%28a%2B4%29+%2A8%28a-2%29%28a%2B1%29%7D%3D+)
![\frac{a-5}{3(2-a)}+\frac{(a-4)}{2(a-2)}= \frac{a-5}{3(2-a)} -\frac{(a-4)}{2(2-a)} = \frac{2(a-5) - 3(a-4)}{6(2-a)} = \frac{2a-10 - 3a+12}{6(2-a)}= \frac{- a+2}{6(2-a)} =\frac {1}{6}](https://tex.z-dn.net/?f=+%5Cfrac%7Ba-5%7D%7B3%282-a%29%7D%2B%5Cfrac%7B%28a-4%29%7D%7B2%28a-2%29%7D%3D+%5Cfrac%7Ba-5%7D%7B3%282-a%29%7D+-%5Cfrac%7B%28a-4%29%7D%7B2%282-a%29%7D+%3D+%5Cfrac%7B2%28a-5%29+-+3%28a-4%29%7D%7B6%282-a%29%7D+%3D+%5Cfrac%7B2a-10+-+3a%2B12%7D%7B6%282-a%29%7D%3D+%5Cfrac%7B-+a%2B2%7D%7B6%282-a%29%7D+%3D%5Cfrac+%7B1%7D%7B6%7D)
значит искомое число равно 1/6*4=4/6=2/3
ответ: 2/3
1- 3, 2) a=1, b=5, c=-4; 3) х(х+3)=180, х^2+3x-180=0, D=9+720=729>0, x1=(-3-27)/2=-15, x2=(-3+27)/2=12
Проверка: х1=-15, х2=-15+3=-12 -15*(-12)=180
х1=12, х2=12+3=15 12*15=180
Ответ: -15 или 12
Ответ:
1) 4,228 - 2,781 = 1,447
2)26,875 - 0,01 = 26,865
3)425,63 - 148,35 = 277,28
Пошаговое объяснение:
Начерти прямой угол и замер расстояние между В и С и раздели этот отрезок пополам, потом из точки А, проведи линию к центру отрезка ВС.
2^(2x) + 3<span> = 128
2^(2x)=125=5^3
log_2 5^3=2x
x=(log_2 5^3)/2=(3*log_2 5)/2=(3*lg 5)/(2*lg 2)</span><span>≈3.48</span>