Answer:

Step-by-step explanation:
we have the expression:

We need to multiply the two terms in the first parenthesis by the two terms in the second parenthesis:

we solve each term taking into account the law of signs
(-)(-)=+
and
(+)(-)=-
also for the first term we use that 
thus we have:

it can be simplified a little more if we factor an r of the second and third term:

Answer:
-4/13
Step-by-step explanation:
Answer:
D
Step-by-step explanation:
= 34/5 × 19/4
= 646/20
= 
Answer:
30 degrees.
Step-by-step explanation:
The ladder that extends from the floor to the storeroom makes a right triangle. The ramp is the hypotenuse measuring 10 m and the elevation of the storeroom is the opposite side. The angle of elevation is the arcsin of the quotient of the 5/10. Thus, the answer is 30 degrees.
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