Answer:
A
Step-by-step explanation:
Distance between 2 points

☆ (x₁, y₁) is the first coordinate while (x₂, y₂) I'd the second coordinate.
Length of RS
![= \sqrt{ {[ - 1 -( - 4)] }^{2} + (9 - 1)^{2} } \\ = \sqrt{( - 1 + 4)^{2} + 8^{2} } \\ = \sqrt{ {3}^{2} + 64 } \\ = \sqrt{73} \\ = 8.54 \: (3 \: s.f.)](https://tex.z-dn.net/?f=%20%3D%20%20%5Csqrt%7B%20%7B%5B%20-%201%20-%28%20-%204%29%5D%20%7D%5E%7B2%7D%20%20%2B%20%289%20-%201%29%5E%7B2%7D%20%7D%20%20%5C%5C%20%20%3D%20%20%5Csqrt%7B%28%20-%201%20%2B%204%29%5E%7B2%7D%20%20%2B%208%5E%7B2%7D%20%7D%20%20%5C%5C%20%20%3D%20%20%5Csqrt%7B%20%7B3%7D%5E%7B2%7D%20%20%2B%2064%20%7D%20%20%5C%5C%20%20%3D%20%20%5Csqrt%7B73%7D%20%20%5C%5C%20%3D%208.54%20%5C%3A%20%283%20%5C%3A%20s.f.%29)
Thus, RS is about 8.5 units.
X axis is the ones that goes left and right
(x,y)
symetric about the x axis means that the vertical distance from the x axis is the same for 2 points that are symetric about the x axis
y is height
(x,y)
(5,2)
2 is height
distance from x axis
therefor the other point is -2
(5,-2)
the other vertex is at (5,-2)
3/4 + 1/2
multiply 1/2 denominator and numerator by 2 to match 3/4
= 3/4 + 2/4 = 5/4 (copy same denominator add numerator)
2/6 + 1/3
divide 2/6 denominator and numerator by 2 to match 1/3
= 1/3 + 1/3 = 2/3 (copy same denominator add numerator)
5/9 + 2/3
multiply 2/3 denominator and numerator by 3 to match 5/9
= 5/9 + 6/9 = 11/9 (copy same denominator add numerator)
6/9 -1/5
cross multiply 6x5 - 1x9 for numerator
for denominator multiply 9x5
=30/45 - 9/45= 21/45
divide num and den by 3
=7/15
5/8-1/3
cross multiply 5x3-1x8 for numerator
multiply 8x3 for denominator
= 15/24 -8/24 =7/24
No.Because 14/2=7 and 7*3=21 so $21 is the answer.