Discover Questions

The function f is f(x)= (x+4)(x-a), the graph of f is a parabola , a is const. The x coord. is b/w 1 and 3, which is a?
A. -2
B. 1
C. 5
D. 9? There are many different types of fossils in our hypothetical rock layers. What do the majority of these fossils have in common? SO2 -> ? K2Cr2O7? I'm trying to find a way to get my grades up in maths and I don't know how to focus on just studying does anyone know how to help? How much blood do you give when you give it? And how often is one allowed to donate?