SOLUTION: Hello Sir/Mame, I would be grateful for any assistance regarding the following question. 'In my pocket, I have some 20 cent coins and 50 cent coins. I have seven more 50 cent coin

Algebra ->  Finance -> SOLUTION: Hello Sir/Mame, I would be grateful for any assistance regarding the following question. 'In my pocket, I have some 20 cent coins and 50 cent coins. I have seven more 50 cent coin      Log On


   



Question 638399: Hello Sir/Mame, I would be grateful for any assistance regarding the following question.
'In my pocket, I have some 20 cent coins and 50 cent coins. I have seven more 50 cent coins than 20 cent coins and have a total of $16.10. how many of each coin do I have?'
My teacher would like me to use algebra as a replacement of 'Trial and Error'
Thank you!
Sash Lack

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +x+ = number of 20 cent coins
+x+%2B+7+ = number of 50 cent coins
given:
+x%2A20+%2B+%28+x+%2B+7+%29%2A50+=+1610+ ( in cents )
+20x+%2B+50x+%2B+350+=+1610+
+70x+=+1610+-+350+
+70x+=+1260+
+x+=+18+
+x+%2B+7+=+25+
You have 18 twenty cent coins and
25 fifty cent coins
check answer:
+x%2A20+%2B+%28+x+%2B+7+%29%2A50+=+1610+
+18%2A20+%2B+%28+18+%2B+7+%29%2A50+=+1610+
+360+%2B+1250+=+1610+
+1610+=+1610+
OK