4) |x|=6,3 : 7; 6) |x|=4.2 : 5;
|x|=0.7; |x|=0.84;
x=0.7 или x= -0.7 x=0.84 или x= -0.84
Ответ: x= -0.7; 0.7 Ответ: x= -0.84; 0.84
5)6*|x|=6.9+2.7; 7) 4*|x|=2.2-0.6;
6*|x|=9.9; 4*|x|=1.6;
|x|=9.9 : 6; |x|=1.6 : 4;
|x|=1.65; |x|=0.4;
x=1.65 или x= -1.65 x=0.4 или x= -0.4
Ответ: х= -1.65; x=1.65; Ответ: x= -0.4; 0.4
Первый пример расписал, остальные так же.
![1.\;7!\cdot8=1\cdot2\cdot3\cdot4\cdot5\cdot6\cdot7\cdot8=8!\\ 2.\;16\cdot15!=\ldots=16!\\ 3.\;12!\cdot13\cdot14=14!\\ 4.\;K!\cdot(K+1)==(K+1)!\\ 5.\;(K-1)!\cdotK=K!\\ 6.\;(K-1)!\cdot K\cdot(K+1)=(K+1)!](https://tex.z-dn.net/?f=1.%5C%3B7%21%5Ccdot8%3D1%5Ccdot2%5Ccdot3%5Ccdot4%5Ccdot5%5Ccdot6%5Ccdot7%5Ccdot8%3D8%21%5C%5C%0A2.%5C%3B16%5Ccdot15%21%3D%5Cldots%3D16%21%5C%5C%0A3.%5C%3B12%21%5Ccdot13%5Ccdot14%3D14%21%5C%5C%0A4.%5C%3BK%21%5Ccdot%28K%2B1%29%3D%3D%28K%2B1%29%21%5C%5C%0A5.%5C%3B%28K-1%29%21%5CcdotK%3DK%21%5C%5C%0A6.%5C%3B%28K-1%29%21%5Ccdot+K%5Ccdot%28K%2B1%29%3D%28K%2B1%29%21)
Первый: 3/8+1/4=3+2 /8=5/8
второй: 2/3-1/6= 4-1 /6=3/6=1/2
третий: 7/12-1/2= 7-6 /12= 1/12
четвертый: 2/9+2/3= 2+6 /9= 8/9