Answer:
(running water, city water, town water, municipal water, sink water, etc.) is water supplied to a tap (valve). Its uses include drinking, washing, cooking, and the flushing of toilets. Indoor tap water is distributed through "indoor plumbing", which has existed since antiquity but was available to very few people until the second half of the 19th century when it began to spread in popularity in what are now developed countries. Tap water became common in many regions during the 20th century, and is now lacking mainly among people in poverty, especially on Indian Reservations in the US and in developing countries.
Question:
Prove that:

Answer:
Proved
Step-by-step explanation:
Given

Required
Prove

Subtract tan(10) from both sides


Factorize the right hand size

Rewrite as:

Divide both sides by 


In trigonometry:

So:
can be expressed as: 
gives


In trigonometry:

So:

Because RHS = LHS
Then:
has been proven
Answer:
-2
Step-by-step explanation:
slope formula is (y2-y1)/(x2-x1)
1 - -7 / -1 - 3
8 / -4
-2
Your answer will be choice A recall complementary angles total 90 degrees and supplementary angles total 180 degrees