That you
Simplify the product of (3+ J7/3-17)
found in the previous step.
(3 + 7)(3-7)=

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link:

producers: apple trees, potatoes, carrots, grains, acorns, cabbage, grass, corn, lettuce

consumers: deer, mice, rabbits, chickens, squirrels, horses, worms, cows

predators: eagles, frogs, wolves, owls