15-6+48-1,25+13+17-4+3000=9+46,75+30+2996=3081,75
1. 864
(48*7:6-4*5)=36
900-36=864
2.74
(900-48*7)=6104
6104:6-4*5=74
3.864
(48*7:6-4)=52
4.60
13,8:3 5/6-3 1/5=69/5:23/6-16/5= 69*6/5*23-16/5=18/5-16/5=2/5
X^2 - 6x + 8 = 0
(x - 4 )* ( x - 2) = 0
x = 4;
x = 2;