Answer:
-9
Step-by-step explanation:

Your calculator can help with this.
The height of the triangular base of the pyramid is calculated through the equation,
h = (cos x)(18 in)
where h is height and x is half of the angle of the triangle. Since the triangle is equilateral, the value of x is 30°. Substituting,
h = (cos 30°)(18 in)
h = 15.59 in
Thus, the height of the base is approximately 15.59 inches.
Answer:
92
Step-by-step explanation:
3x+15=0
<=> 3x=-15
<=> x= -15/3
<=> x= -5
Vậy nghiệm của đa thức 3x+15 là -5