Answer:
c-c+a+|a|
5-5+4+|4|
8
Step-by-step explanation:
Negative exponents work like this:

So, in order to evaluate a negative exponent, you simply have to invert the base, and then raise to the positive equivalent of the exponent.
As an example, here are the first three exercises:



You can work out the rest applying this logic.
I believe the answer is acute. Hope this helps!!
Area covered by the solar cells = 269.5 m^2
Area of one cell = 150 cm^2
Convert the area of one cell to m^2 by using the conversion factor 1m^2 = (100cm)^2 => 1 = 1m^2 / 1000 cm^2
=> 150 cm^2 * [1m^2 / 1000 cm^2] = 0.150 m^2
Now finf the number of times that 0.150 is contained in 269.5 by dividing 269.5 by 0.150
269.5 = 0.150 = 1,796.67
Which means that the number of cells is betwee 1796 and 1797.