Answer:
Jamie has 14 nickels and 56 dimes
Explanation:
Start by identifying labels for the # of dimes and nickles. Lets use x for nickels and y for dimes.
From here you can make two formulas (x + y = 70) and (5x + 10y = 630) when you put them into a graphing calculator they should intersect at (14,56) which means the x = 14 and y = 56