-4

We'll solve the system of the inequalities in this way:

-4 < 5-3x (1)

5-3x < 20 (2)

We'll solve the first inequality, by isolating to one side the unknown. For this reason, we'll subtract 5 both sides:

-4-5<-5+5-3x

-9<-3x

We'll divide by -3, changing the direction of the inequality:

x<3

We'll solve now the inequality (2):

5-3x < 20 (2)

We'll subtract 5 both sides:

5-5-3x<20-5

-3x<15

We'll divide by -3, changing the direction of the inequality:

x>-5

So, for the double inequality to hold, x has to have values in the interval (-5,3).