Select the expressions whose value is 4.
(-2)²
|- 4|
- 4÷2
2(-2)

When you answer this can you explain

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?

How can you use synthetic substitution to tell whether a given binomial is a factor of a polynomial?