Brad spent 20 percent of his money to buy a car costing £6800 how much did he have
reply asap

He had 34000 euros total.  Divide 6800 by 0.2 (AKA 20%)

There are few ways but i prefere this way:

100/20=5
6800*5=?
6000*5=30000
800*5= 4000
+
= 34000

=£34000

If you need an equation, it would be y=2x+8, y would be how long it grew, x being weeks.if you need how long he was asleep, it would be 4 weeks if he started with no beard, the equation would be x=8÷2if he did have a beard before hand, the equation would be 2w+x=8