The price of one pound of banana = b
As one pound of oranges costs $0.75 more than one pound of bananas, so, the price of one pound of orange = b+0.75.
The price of 3 pounds of banana = 3b,
and the price of 2 pounds of oranges = 2(b+0.75).
Now, as she pays $4.50 for 3 pounds of bananas and 2 pounds of oranges.
So, for this situation the required equation is
3b + 2(b+0.75) =4.5
On solving this equation, we have
[tex]\Rightarrow 3b+2b+2\times0.75=4.5[/tex]
[tex]\Rightarrow 5b +1.5=4.5[/tex]
[tex]\Rightarrow 5b =4.5-1.5=3[/tex]
[tex]\Rightarrow b =\frac 3 5=0.6[/tex]
Hence, the price of one pound of banana = $ 0.60
and the price of one pound of orange
=b+0.75= 0.60+0.75=$1.35.