The number given in the question is in decimal form. It has to be first changed to fraction and then only can it be changed to a mixed fraction. The calculations have to be done correctly and then the problem is very straight forward.Now let us concentrate on the problem in hand.
Then
6.54 = 654/100
= 327/50
= 6 27/50
From the above deduction we can definitely conclude that the mixed number for 6.54 is 5 27/50. I hope this simple procedure will help you to attempt such type of problems in future without requiring any additional help.
It will take him 21 weeks to have $1250 saved
Probably the subsitution method
y=1/2x
subsitute that fr y
2x+3(1/2x)=28
2x+3/2x=28
times 2 both sides
4x+3x=56
7x=56
divide by 7 both sides
x=8
sub back
y=1/2x
y=1/2(8)
y=4
(x,y)
(8,4)