Question

3. Marcos had 20 coins in nickels and quarters. The total of his coins is $3.00. How many

quarters and nickels does he have?

Answer 1

q=10 n=10

Explanation:

nickel = 5¢ (or 0.05)

quarters = 25¢ (or .25)

`q+n=20\\.25q+.05n=3\\\\\\-.05(q+n)=20(-.05)\\-.05q-.05n=-1\\\\-.05q-.05n=-1\\.25q+.05n=3\\---------\\0.2q= 2\\-- --\\0.2 \\q=10 \\\\10+n=20\\n=20-10\\n=10\\\\.25(10)+.05(10)=3\\2.5+0.5=3`