Answer:
1,124 pennies.
Explanation:
Let x represent the total amount of coins Christine's penny bank can hold.
We know that it is initially 1/5 full. So, the amount of coins in the bank is:

We know that she adds 562 pennies in it. So, we will add 562 to our expression:

And we know that after adding 562 pennies, the bank is now 7/10 full. Therefore:

To find out how many coins the bank can hold, we will simply solve for x.
First, let's multiply both sides by 10 to remove the fractions:

Distribute:

Subtract 2x from both sides:

Divide both sides by 5:

Therefore, Christine's penny bank can hold a maximum of 1,124 pennies.
And we're done!