When more offspring than can survive are produced, it is called overproduction. Variation among these offspring exists. The offspring with variations more suited to their environments will be more likely to survive.
Simple.....
you have

to find what a is....simplify/multiply both sides....

simplifying it too....
18=7a


Thus, your answer, C.
To make things easier to measure
Answer:
12.04
Step-by-step explanation:
square root 2(9x9 + 6x6) = 12.04