Answer:
It's elevation at the surface is 0, and the elevation twenty feet below is -20.
Step-by-step explanation:
The surface level is 0, and diving 20 feet under means 0 - 20, which is negative 20, or -20.
hope you can understand
x=-7
-30=5(x+1)
6-1(x+1)
x=-1-6
=-7
8 battery =12
20 battery =?(x)
8x=240
x=240÷8
x=30
for 20 battery..it would cost 30