Answer:
0?8
Step-by-step explanation:
Cos(A) = Adjacent/hypotenuse
Cos(A) = 36/45
=0.8
Answer:
19 - (6/5)j
Step-by-step explanation:
In this expression we have addition, subtraction and multiplication.
According to order of operations rules, mult. and div. must be carried out before add. or subt.
Therefore, we begin with 17+(-4), which becomes 17 - 4, or 13.
Next we see -4/5j, by which I assume you mean -4/5 * j.
Summarizing what we have so far:
13 - (4/5)j - 2/5j + 6
Combining the j terms, we get
13 - (6/5)j + 6, which collapses to 19 - (6/5)j.
Answer:
Metals which react with steam form the solid metal oxide and hydrogen gas.
In general, the more reactive the metal, the more rapid the reaction. Aluminium is unusual, because it is a reactive metal that does not react with water. Its surface forms a protective layer of aluminium oxide that keeps water away from the metal below.
The apparatus used to react a metal with steam and collect the gas produced is shown below.
Actually, the answer is not A, if you're saying A is the first choice above. That's incorrect. You will need to use the Geometric mean for right triangles here to figure out what the value of a is. We will use this form:

. We have a value for YZ of 3; side a is XZ. That means in order to solve this we need WZ, which we can find using pythagorean's theorem. 3^2 + 4^2 = c^2 and 9 + 16 = c^2 and c = 5. Now we fill in accordingly:

. Cross-multiply to get 3XZ=25 and side XZ is

. XZ is 25/3 and YZ is 3, so 25/3 - 3 = XY. That means that XY (side a) = 16/3 or 5 1/3, choice B, or the second one down.