5 days of a year in a fraction
-2x+y=-4
2x-y-4=0
system of equation
[1 1 1, 2 3 -1, 3 -1 -1] [6 7 6] solve using inverse coefficient matrix method
$1,05^{t-1}$ =2
-10*(20+(-5))=
{x>-2
4x+3y=30
x-y=4
x-3y=-3
-x+3y=3
