1. Take 300g of sulfuric acid A and 250g of sulfuric acid B, and add 200g of water to make 50% sulfuric acid;

2. Take 200g of sulfuric acid A and 150g of sulfuric acid B, and add 200g of pure sulfuric acid to make 80% sulfuric acid.

3. So, what are the concentrations of sulfuric acid A and B respectively?

1 Before adding water, * * contains sulfuric acid: (300+250+200)×50%=375(g).

2 * * contains sulfuric acid before adding sulfuric acid: (200+150+200) × 80%-200 = 240 (g).

Now suppose that the sulfuric acid solution in 1 (before adding water) is doubled to obtain:

A, A: 600g B: 500g * * * Sulfuric acid: 325x2 = 750 (g).

Enlarge the sulfuric acid solution in 2 (before adding sulfuric acid) by 3 times to obtain:

B, A: 600g B: 450g *** Sulfuric acid: 240×3=720(g).

In solution B, A is 50 grams more than B, and in sulfuric acid, 30 grams more. It can be concluded that the concentration of B is (750-720) ÷ (500-450) ×100% = 60%.

The easily available concentration of solution A is 75%.

Second, one-dimensional linear equation

According to the above analysis, it is easy to list equations.

Answer over!