Answer:
cubic trinomial
Step-by-step explanation:
can I have brainllest
Answer:
90 g of water should be added and he will make 900 g of solution.
Step-by-step explanation:
Let x g be the amount of salt Ilya add to 810g of water to make 10% solution. Then 810+x g is the amount of new solution. Thus,
810+x - 100%,
x - 10%.
Mathematically,

So 90 g of water should be added and he will make 810+90=900 g of solution.
All you have to do is combine 3x and 5x to = 8x. You can't combine 8x and 67y because they have different variables. so it's 8x+67y.