# Simultaneous Equations - How to form the equation

• Mar 17th 2010, 11:38 AM
Simultaneous Equations - How to form the equation
Juanita saves 20 cent and 50 cent coins in a money jar. After counting her money, she has 299 coins in total which ass up to \$94.

I) Taking x to be the number of 20 cent coins and y to be the number of 50 cent coins, write down two equations in x and y to represent this information.

Im just struggling trying to form the equation, I can solve it after that.
I think it would be something like this
20x + 50y = 299
20x + 50y = 940

I was thinking along these lines, Can somebody help?
But then when you change the signs, you cross out both the x and the y, Its confusing me.
• Mar 17th 2010, 11:56 AM
earboth
Quote:

Juanita saves 20 cent and 50 cent coins in a money jar. After counting her money, she has 299 coins in total which ass up to \$94.

I) Taking x to be the number of 20 cent coins and y to be the number of 50 cent coins, write down two equations in x and y to represent this information.

Im just struggling trying to form the equation, I can solve it after that.
I think it would be something like this
x + y = 299
20x + 50y = 9400

...

...and now continue!
• Mar 17th 2010, 06:02 PM
bjhopper
forming an equation
Quote:

Originally Posted by earboth
...and now continue!

i always find it easier to write the equation in one unknown .If x is the number of 50 cent coins then 299-x equals the 20 cent coins You then write .5x +.2(299-x) =94

bjh