**PLEASE HELP** For the following question what is the value of X to the nearest 10th? (Give me answer and explanation please!!)

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

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)

You just purchased two coins at a price of $670 each. because one of the coins is more collectible, you believe that its value will increase at a rate of 7.1 percent per year, while you believe the second coin will only increase at 6.5 percent per year. if you are correct, how much more will the first coin be worth in 15 years?