An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system. These biotic and abiotic components are linked together through nutrient cycles and energy flows. ... Ecosystems are controlled by external and internal factors.
It's quite simple. Look:
Lets let S- be the age of Sally and B- can be the age of Beth
S+B=60
S-6=3(B-6)
S-6=3B-18
S=3B-18+6
S=3B-12
3B-12+B=60
4B=60+12
4B=72
B=72/4
B=18
B=60-18
B=42
The ages are (B)18 and (S)42
Hope this helps!! :)
Answer:
add a picture reading this is too hard
Step-by-step explanation:
The answer to that would be 8 !!!(:
