Question

solve 1 ) -91÷(-7)
2 )-10+30-20+50.
3) 4,-12,6

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Answer 1

Answer:

Firstly, the disappearance of biodiversity and aquatic ecosystems. Also, humans are harmed by the alteration in the food chain and by contracting illnesses when drinking or using contaminated water. As you can see, water pollution has a great impact in the environment.

Answer 2

Answer:

30-20

Step-by-step explanation:

1. olve 1 ) -91÷(-7)

2 )-10+30-20+50.

3) 4,-12,6