Answer:
The original selling price would be $ 515.87 ( approx )
Step-by-step explanation:
Let x be the original selling price ( in dollars ),
After marking down 10%,
New selling price = x - 10% of x = x - 0.1x = 0.9x
Again after marking down 30%,
Final selling price = 0.9x - 30% of 0.9x
= 0.9x - 0.3 × 0.9x
= 0.9x - 0.27x
= 0.63x
According to the question,
0.63x = 325

Hence, the original selling price would be $ 515.87.
We have that

we know that
Is the equation of a vertical parabola open down
so
the vertex is a maximum
step 1
convert the equation of the parabola in the vertex form

the vertex (h,k) is the point (0,36)
Part a) The point on the graph where the height of the tunnel is a maximum is (0,36)
Part b) The points on the graph where the height of the tunnel is zero feet is when y=0
so
for y=0

the points are (-6,0) and (6,0)
see the attached figure
Answer:
D. sin m∠C = 2 square root of 5 all over 5
Step-by-step explanation:
The triangle ABC is a right angled triangle. The angle ∠C is where we are asked to find. The side AB measures 6 , AC measures 3 and the side BC measures 3√5.
The longest side of a right angle triangle is the hypotenuse, that means the side with length 3√5 is the hypotenuse.
Therefore side BC is the hypotenuse side and we are asked to find the angle C. AB is the opposite side while AC is the adjacent side.
Using
sin C = opposite/hypotenuse = 6/3√5 = 2/√5 = 2√5/5
cos C = adjacent/hypotenuse = 3/3√5 = 1/√5