In desperate need of system of equations math hw help?

Question

the problem is: a chemist has 1000g of a solution that is 40% acid. How many grams of water must be added to reduce the acidity to 25%? the answer in the back of the book says 600. i just need someone to show me how to do it in system of equations form because we need to show our work.

Answer 1

I don't know if this is what you need, but I would start out by saying there are 400g of acid because 1000g x 40% = 400g. Then you set it up to 400g = 25% x and solve for x. That gives you 1600g. Then you do 1600g - 1000g (the original amount) and you get an extra 600g (the answer).

Answer 2

1000 x .4 = 400 grams of acid
for 25% solutions you need 3 parts water (75%) to one part acid (25%).
so you need 400 x 3 g (1200g) of water.
1000-400=600g of water right now.
1200-600=600g of water.

You could do it another way.