v(t)=t²-4t+3
a(t)=2t-4
2t-4=0
2t=4
t=2
Ответ: 3.2
Х=1,23434
10х=12,3434
1000х=1234,3434
1000х-10х=1234,3434-12,3434
990х=1222
х=1222/990
![\frac{5}{x-1}- \frac{5}{x+1}=1 \\ \frac{5(x+1)-5(x-1)}{(x-1)(x+1)}=1 \\ \frac{10}{(x-1)(x+1)}=1 \\ (x-1)(x+1) \neq 0,x \neq 1,x \neq -1 \\ (x-1)(x+1)=10 \\ x^2-1=10 \\ x^2=11 \\ x_1= \sqrt{11},x_2=- \sqrt{11} \\ - \sqrt{11}=-3.3166...](https://tex.z-dn.net/?f=+%5Cfrac%7B5%7D%7Bx-1%7D-+%5Cfrac%7B5%7D%7Bx%2B1%7D%3D1+%5C%5C++%5Cfrac%7B5%28x%2B1%29-5%28x-1%29%7D%7B%28x-1%29%28x%2B1%29%7D%3D1+%5C%5C++%5Cfrac%7B10%7D%7B%28x-1%29%28x%2B1%29%7D%3D1+%5C%5C+%28x-1%29%28x%2B1%29+%5Cneq+0%2Cx+%5Cneq+1%2Cx+%5Cneq+-1+%5C%5C+%28x-1%29%28x%2B1%29%3D10+%5C%5C+x%5E2-1%3D10+%5C%5C+x%5E2%3D11+%5C%5C+x_1%3D+%5Csqrt%7B11%7D%2Cx_2%3D-+%5Csqrt%7B11%7D+%5C%5C+-+%5Csqrt%7B11%7D%3D-3.3166...++++++)
значит отрицательный корень уравнения содержится в промежутке (-4;-3)
1) 16a+2y= 16×1/8+2×(-1/6)=2-2/3= 6-2/3=4/3= 1 1/3
2) 2+0.3×(-9)=2-2,7=-0,7
2-0,3×(-9)=2+2,7=4,7
-0,7<4,7
3) a) 5a+7b-2a-8b= 3a-b
b) 3(4x+2)-5= 12x+6-5= 12x+1
в) 20b-(b-3)+(3b-10)= 20b-b+3+3b-10=22b-7
4)-6(0.5x-1,5)-4,5x-8= -3x+9-4,5x-8= -7,5x+1
-7,5×2/3+1= -15/2×2/3+1=-30/6 +1= -5+1=-4
5) s=tv1+tv2
s=3×80+3×60=240+180=420км
6) 2p-(3p-(2p-c))= 2p-(3p-2p+c)= 2p-3p+2p-c= p-c