Answer:
Step-by-step explanation:
Initially Sam and Ali have the same amount. After Sam gives Ali $ 15, the ratio of amounts becomes 7 : 5.
Let the initial amount with either of Sam and Ali be [tex]x[/tex].
[tex]x[/tex] is in dollars.
After the transaction, Sam has [tex]x-15[/tex] and Ali has [tex]x+15[/tex].
Now, Ratio of Ali's to Sam's is 7:5
So, [tex]\dfrac{x+15}{x-15}=\dfrac{7}{5}\\\\5x+75=7x-105\\2x=180\\x=90[/tex]
∴ Initially both had $ 90.