How do I find the excluded values? Please help I have a test tomorrow.

Zoe placed colored blocks on a scale in science class. each block weighed 0.8 ounces. the total weight of all the colored blocks was 12.8 ounces. how many blocks did zoe place on the scale? write and solve an equation to find the answer.

If f(x)= sqrt4x+9+2, which inequality can be used to find the domain of f(x)?

In a class, there are 12 girls. if the ratio of boys to girls is 5: 4 how many boys are there in the class