Can someone show me how to do this one correctly?

ANSWER:
Juwan has 19 dimes and 6 quarters in his pocket.
STEP-BY-STEP EXPLANATION:
From the statement we can establish the following system of equations:
Taking into account that one dime is 10 cents and a quarter is 25 cents.
Let x be the number of dimes
Let y be the number of quarters
[tex]\begin{gathered} x+y=25\rightarrow x=25-y\text{ (1)} \\ 10x+25y=340\text{ (2)} \end{gathered}[/tex]We solve the system of equations by means of the substitution method, we substitute equation (1) in (2):
[tex]\begin{gathered} 10\cdot(25-y)+25y=340 \\ 250-10y+25y=340 \\ 15y=340-250 \\ y=\frac{90}{15} \\ y=6 \\ \\ \text{therefore, for x:} \\ x=25-6 \\ x=19 \end{gathered}[/tex]Therefore they are 19 dimes and 6 quarters