Question

If a 9.0-volt battery is placed across a 5.0-ohm resistance, the current will be _____ amperes.

Answer 1

This is physics, electricity.
I'll break it down for you, very easy:
you have to use the formula V=IR
where V= voltage in volts (V)
I= current in Amperes (A)
R= resistance in ohms (Ω)

so what you require is I, current there you have to rearrange the formula to subject current;
I=V/R
=9/5= 1.8Ω (ans)