60+50-40+30-20-10
всё просто :))
1) 0,5x + 3 =0,2x
0,5x - 0,2x = -3
0,3x = -3
x =
![- \frac{3}{0,3}](https://tex.z-dn.net/?f=-+%5Cfrac%7B3%7D%7B0%2C3%7D+)
= -10
2) -0,4a - 14 = 0,3a
0,3a + 0,4a = -14
0,7a = -14
a = <span>
![- \frac{14}{0,7}](https://tex.z-dn.net/?f=-+%5Cfrac%7B14%7D%7B0%2C7%7D+)
= -20
3) </span><span>-12n - 3 = 11n - 3
11n + 12 n = 3 - 3
23n = 0
n = 0
4) 7m + 1 = 8m + 9
8m - 7m = 1 - 9
m = -8</span>
Получим равную ей десятичную дробь
например 5,860000000=5,68
-2a(-9)(-5b)=18a(-5b)=-90ab
2x-6x-3=0. -4x-3=0 -4x=3. - 3 дробь 4