2t*5t+2t*9+4.5*5t+4.5*9 = 0
10t(в квадрате)+18t+22.5t+40.5t=0
Я спешу, поэтому дорешайте сами
350 - 100%
315 - х%
350х = 315*100
350х=31500
х= 31500/350
х=90%
X + 6x - 4 = 10
7x - 4 = 10
7x = 14
x = 14/7
x = 2
<span>-9(4+x)=8x-2
-36 -9x -8x = -2
-17x = -2 +36
-17x = 34
x = 34/ -17
x = -2</span>