Answer: The answer is 381.85 feet.
Step-by-step explanation: Given that a window is 20 feet above the ground. From there, the angle of elevation to the top of a building across the street is 78°, and the angle of depression to the base of the same building is 15°. We are to calculate the height of the building across the street.
This situation is framed very nicely in the attached figure, where
BG = 20 feet, ∠AWB = 78°, ∠WAB = WBG = 15° and AH = height of the bulding across the street = ?
From the right-angled triangle WGB, we have

and from the right-angled triangle WAB, we have'

Therefore, AH = AB + BH = h + GB = 361.85+20 = 381.85 feet.
Thus, the height of the building across the street is 381.85 feet.
We need to convert this equation to slope-intercept form first.
We can do that by solving for y.
x - 5y = 15
<em><u>Add 5y to both sides.</u></em>
x = 5y + 15
<em><u>Subtract 15 from both sides.</u></em>
x - 15 = 5y
<em><u>Divide both sides by 5.</u></em>
y = 1/5x - 3
We now know the slope is 1/5.
The slope of the line perpendicular to the line with a slope of 1/5 is -5.
The slope of a perpendicular line is the negative reciprocal of the original slope.
Using a graphing calculator, we know the y-intercept of the line that is perpendicular to the original line must have a y-intercept of -6 to run through the points (-2, 5).
The equation of the new line is y = -5x - 6.
Hello :
<span>3.6/y=1.2/2
1.2 y = 2(3.6)
y = 2(3.6)/1.2
y=6</span>
Answer:
x= -10
Step-by-step explanation:
The equation is y2-y1 over x2 over x1 so
1-(-2) over -9-(x)=3
1+2=3 over -9-(x)
3/-9-x times -9-x = 3 times -9-x
3=3(-9-x)
3=-27-3x
3+27=-3x
30= -3x
-10= 3x
hope it helps man!!! :)
ps may i have brainliest so i can level up