4 - lg ^2(x) =3 * lg(х)
пусть lg(х) = y
4 - y^2 = 3y
y^2 + 3y - 4 = 0
По теореме Виетта: y1 + y2 = -3 и y1 * y2 = -4
y1 = 1 или y2 = -4 =>
lg(х) = 1 или lg(х) = -4 =>
<span>x = 10 или x = 10^(-4) = 0.0001</span>
1. х=7,19-5,14=2,05
2. 3,6-х=13,6+4,9
х=3,6-13,6-4,9=-14,9
8x=-16
x=-2
-2*2+3y=2
-4+3y=2
3y=6
y=2
Ответ:(-2;2)
1. 1) -204/100 : 1/25 = -204/100 * 25 = -204/4 = -51
2) 361/100 : - 19/40 = - 361/100 * 40/19 = -38/5 = -760/100 = - 7,6
3) -51 +7,6 = -43,4
4) -434 / 10 : (-14/5) = -434/10 * (-5/14) = 31/2=15,5
5) 6/10 : (-9/10) = 6/10 * (-10/9) = -2/3
6) 155/10 - 2/3 = 465/30 - 20/30 = 445/30 = 14 5/6
2. 1)77/10 : (-11/40) = - 77/10 * 40/11 = -28
2) 38/10 : -1/20 = - 38/10 *20 = -76
3) -28+76 = 48
4) 48* -5/16 = -15
5) 4/10 : -36/100 = -4/10 * 100/36 = -10/9
6) -15 + 10/9 = -135/9 + 10/9 = -125 / 9 = -13 8/9