Х×(2х+13) = 0
либо х = 0 либо 2х+13 = 0 х = - 13/2 = - 6.5
ответ: либо х = 0 либо х = - 6.5
F⁾(x)=((x³-4x)(7x⁴+5x-1))⁾=(3x²-4)(7x⁴+5x-1) + (x³-4x)(28x³+5) =
=21x⁶+15x³-3x²-28x⁴-20x+4 +28x⁶+5x³- 112x⁴-20x = 49x⁶-140x⁴+20x³-3x²-40x+4
10с-5=1
10с=1+5
с=6/10
с=3/5
0,49t²-(t-p)²=(0,7t-(t-p))·(0,7t+t-p)=(0,7t-t+p)(1,7t-p)=(p-0,3t)(1,7t-p).
a²-b²=(a-b)(a+b) , a=0,7t ,b= t-p.
1)из 1 выражаем у=6х-2 и представляем во 2
-х+6х-2=-1
5х=1
х=1/5
у=6*1/5-2=6/5-10/5=-4/5