I'm slow I need help :(

Which values of p and q result in an equation with exactly one solution? px-43=-42x+q choose all answers that apply: a) p=-43 and q=-43 b) p=42 and q=43 c) p=43 and q=−42 d) p=42 and q=42

How many kilograms of a 5% salt solution and how many kilograms of a 15% salt solution must be mixed together to make 45kg of an 8% salt solution?

The area of a circle is equal to 1 dm². find the radius of the circle.