Y - y1 = m(x - x1)
slope(m) = -1/2
(-4,-2)...x1 = -4 and y1 = -2
now we sub
y - (-2) = -1/2(x - (-4) =
y + 2 = -1/2(x + 4) <=====
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.