Answer: Last Option

Step-by-step explanation:
The initial height of the plant of species A is 25 cm and grows 3 centimeters per month.
If m represents the number of months elapsed then the equation for the height of the plant of species A is:

For species B the initial height is 10 cm and it grows 8 cm each month
If m represents the number of months elapsed then the equation for the height of the plant of species B is:

Finally, the system of equations is:

The answer is the last option
The value of x is 13, from the values of x the values of a,b and c becomes 5, 12 and 13, which is obtained by using Pythagorean theorem.
Step-by-step explanation:
The given is,
a = 5
b = x - 1
c = x
Step:1
Pythagorean theorem is,
................................(1)
( It states that the area of the square whose side is the hypotenuse is equal to the sum of the areas of the squares on the other two sides )
From the given values the equation (1) becomes,

(
)
25 + (
+ 1 - 2x ) = 
25 + 1 -2x = 0 ( ∵ Eliminate
in both sides)
26 = 2x
x = 13
Step:2
From the values of x,
a = 5
b = ( 13 - 1 ) = 12
c = 13
Result:
The value of x is 13, from the values of x the values of a,b and c becomes 5, 12 and 13, which is obtained by using Pythagorean theorem.