There are 10 coins in a jar. some are dimes and the rest are nickels. the coins are worth a total of 70 cents. which system of equations represent the situation

Which equation and solution can be used to solve this problem? thirteen less than a number is sixteen. 13-n=16: add 13 to both sides. the answer is 29. n+13=16: subtract 13 from both sides. the answer is 3. n+16=13 subtract 13 from both sides. the answer is 3. n-13=16: add 13 to both sides. the answer is 29.

Ineed with number 6 , explain how to get 1978

Ihonestly have no clue if it's each or none.