Answer:
The angles
are used to prove the similarity of triangles VWZ and YXZ.
Step-by-step explanation:
Given information: 
Two triangles are called congruent if their corresponding sides are in same proportion or the corresponding angles are same.
If two corresponding sides of triangle have same proportion and their inclined angle is same, then by SAS rule of similarity both triangles are similar.
From the given figure it is noticed that the ∠VZW and ∠YZX are vertically opposite angles. The vertically opposite angles are always equal.
(Vertically opposite angles)
(Given)
By SAS rule of similarity

Therefore the angles
are used to prove the similarity of triangles VWZ and YXZ.
Answer:
Mostly correct
For Q3, you are doing great, you remembered that negative numbers can happen if the exponent is an odd number.
For Q4, I think you were confused with the fractions,
4(i)

4(ii) is also wrong but I'll let you try to fix it yourself following what I given you for 4(i). You should get 1/64
Hope this helps!
2=2*1,1*2
24=1*24,2*12,6*4,3*8
19=2*8+3
2x²+19x+24
(2x+3)(x+8)
or
2x(x+8)+3(x+8)
2x²+16x+3x+24
2x²+19x+24
Answer:
∠ I = 39°, ∠ J = 51°, ∠ K = 90°
Step-by-step explanation:
The sum of the 3 angles in a triangle = 180°
Sum the3 angles and equate to 180
3x + 21 + 5x + 21 + 90 = 180, that is
8x + 132 = 180 ( subtract 132 from both sides )
8x = 48 ( divide both sides by 8 )
x = 6
Then
∠ I = 3x + 21 = 3(6) + 21 = 18 + 21 = 39°
∠ J = 5x + 21 = 5(6) + 21 = 30 + 21 = 51°
∠ K = 90°
Answer:
a) Margin of error = 166.311
b) sample size ≥ 62
Step-by-step explanation:
Given:
Average cost = $1599
Sample size = 50 persons
Standard deviation = $600
Confidence level is 95%
a) Margin of error = 
Now for confidence level of 95% z-value = 1.96
Thus,
Margin of error = 
or
Margin of error = 166.311
b) For Margin of error ≤ 150
≤ 150
or
≤ 150
or
≤ √n
or
√n ≥ 7.84
or
n ≥ 61.4656
Therefore,
sample size ≥ 62