Draw a diagram to illustrate the problem as shown in the figure below.
Let h the height of the hill. =
At position A, the angle of elevation is 40°, and the horizontal distance to the foot of the hill is x.
By definition,
tan(40°) = h/x h = x tan40 = 0.8391x
(1)
At position B, Joe is (x - 450) ft from the foot of the hill. His angle of elevation is
40 + 18 = 58°.
By definition, tan(58°) = h/(x - 450)
h = (x - 450) tan(58°) = 1.6003(x-450)
h = 1.6003x - 720.135 (2)
Equate (1) and (2).
1.6003x - 720.135 = 0.8391x 0.7612x = 720.135
x = 946.0523
From (1), obtain
h = 0.8391*946.0523 = 793.8 ft
Answer: The height of the hill is approximately 794 ft (nearest integer)
239.99 x 75%(75/100) ~ $180
$180 x 90%(90/100) = $162
Answer:
0
Step-by-step explanation:
7x + -2z = 4 + -1xy
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add 'xy' to each side of the equation.
7x + xy + -2z = 4 + -1xy + xy
Combine like terms: -1xy + xy = 0
7x + xy + -2z = 4 + 0
7x + xy + -2z = 4
Add '2z' to each side of the equation.
7x + xy + -2z + 2z = 4 + 2z
Combine like terms: -2z + 2z = 0
7x + xy + 0 = 4 + 2z
7x + xy = 4 + 2z
Reorder the terms:
-4 + 7x + xy + -2z = 4 + 2z + -4 + -2z
Reorder the terms:
-4 + 7x + xy + -2z = 4 + -4 + 2z + -2z
Combine like terms: 4 + -4 = 0
-4 + 7x + xy + -2z = 0 + 2z + -2z
-4 + 7x + xy + -2z = 2z + -2z
Combine like terms: 2z + -2z = 0
-4 + 7x + xy + -2z = 0
You flip the inequality.
Example: if x > -y and you divide both sides by (-1) then you flip the inequality so: -x < y