First take triangle BDH. We know B is 46 degrees and D is 33 degrees. Since the angles of a triangle equal 180 we get
180 - 46 - 33 = 101 for H.
H is supplementary to x, so their sum is also 180. This gives 180 - 101 = 79.
So x is 79 degrees.
Since there is no picture shown, I just plotted the given data points myself. That is shown in the attached picture. The blue rectangle is rectangle PQRS while the orange one is rectangle JKLM. I believe there are some choices for this question but you forgot to include. Nevertheless, I will give my observations from the given figure.
The tile PQRS is bigger than tile JKLM. A rectangle is a two-dimensional shape that has two sets of equal parallel planes. Thus, its area is equal to the length multiplied by its width.
tile PQRS = (9-5)*(12-7) = 20 units²
tile JKLM = (6-4)*(10-5) = 10 units²
Tile PQRS is larger by 10 units².
In mathematical notation, ∑ means summation. So wherever you see the symbol, you have to sum over all elements in the set. Let's solve the question.
a. ∑m means, to sum all elements in the set m: ∑m = 12 + 15 + 20 + 30 = 77
b. ∑
means to sum all elements in the set f as the square of the elements f = 
c. ∑mf means to sum all elements as the product of the elements of m and f = (12×5) + (15×9) + (20
10) + (30×16) = 875
d. ∑
means to sum all elements as the product of the square of m and f = 
Question 1:
<h3>Answer: The number does <u>not</u> change</h3>
Removing the zero from 0.76 leads to .76 which is the same as before. Both lead to
in scientific notation.
Personally I prefer the zero up front to make the decimal point stand out easier. Of course it's just a preference, so its up to you to decide which you prefer.
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Question 2:
<h3>Answer: Yes the number changes</h3>
Taking the zero out of 10.25 leads to 1.25 which is definitely a different number (and smaller). Therefore, this zero is a significant digit compared to before.