I need a lot of help and please help i need it

An unknown number of kids and buses are getting assigned. when assigning 4 kids to each bus, there are 2 kids that aren't placed in a bus. when assigning 8 kids to each bus, there are 2 empty buses. how many total kids are there?

Both the red and blue line segments stretch from the center of the circle to a point on the circle. the length of the blue segment is 5. how long is the red line segment?

What is the solution of log2  (3x  -  7)  =  3? 4 5