Answer:
4
Step-by-step explanation:
x² = 8x - 16
x² - 8x + 16 = 0
(x - 4)² = 0
x = 4
Answer: Option 'C' is correct.
Step-by-step explanation:
Since we have given that
Distance at which a bird watcher is away from the base of the tree= 45 feet
Length of the tree at the top of which he spots an oriole = 140 feet
As the figure shown below:
In ΔABC,

Hence, the angle of elevation from the bird watcher to the oriole will be

Therefore, Option 'C' is correct.
Remember, you can do anything to an equation as long as you do it to both sides
times both sides by -1
7-5x=2x
add 5x both sides
7=7x
divide both sides by 7
1=x
x=1