The answer is C
The equation has x = 8/10
To get X by itself you need to divide both sides by 8, so the equation should become X = 10/8
Given:
In the given triangle,
With respect to y, Perpendicular = 10 cm and Base = 8 cm
To find the value of y.
Formula
By Trigonometric Ratio we get,

Now,
Putting the values of perpendicular and base we get,

or, 
or, 
Rounding off to the nearest tenth, we have;

Hence,
The value of y is 51.3°.
Answer:
The length of AB is 7.45 units.
Step-by-step explanation:
You can find the length of AB using Cosine Rule, cosθ = adj./hypo. :
θ = 20°
adj. = 7 units
hypo. = AB
cos 20° = 7/AB
AB = 7/cos 20°
= 7.45 units (3s.f)
It's suppose to be -18 so I guess no real number....
1) x= -7
2) x= -5
3) x=-22
4) x =8
Not sure about the last one tho
I tried to help :)