a balloon is inflated such as its radius is 7.00 cm. What is the volume of air inside the balloon in mL

Let the first integer be x. Then the next consecutive integer is x+1.

Translating the word problem into symbols, x(x+1)-20(x+1) = 442.

Then x^2 + x - 20x - 20 = 442

or x^2 - 19x - 462 = 0

Solve by completing the square:

x^2 - 19x + 90.25 - 90.25 - 462 = 0

(x-9.5)^2 - 552.25 = 0

Taking the positive square root of both sides, we get x-9.5 = 23.5, or
x = 33

The two consecutive integers are 33 and 34.

Check: (33)(34)-20(34) = 442 (as expected).

8 0

2 years ago

Evaluate the triple integral ∭ExydV where E is the solid tetrahedon with vertices (0,0,0),(5,0,0),(0,9,0),(0,0,4).

Elan Coil [88]

Answer: $\int\limits^a_E {\int\limits^a_E {\int\limits^a_E {xy} } \, dV$ = 1087.5

Step-by-step explanation: To evaluate the triple integral, first an equation of a plane is needed, since the tetrahedon is a geometric form that occupies a 3 dimensional plane. The region of the integral is in the attachment.

An equation of a plane is found with a point and a normal vector. Normal vector is a perpendicular vector on the plane.

Given the points, determine the vectors:

P = (5,0,0); Q = (0,9,0); R = (0,0,4)

vector PQ = (5,0,0) - (0,9,0) = (5,-9,0)

vector QR = (0,9,0) - (0,0,4) = (0,9,-4)

Knowing that cross product of two vectors will be perpendicular to these vectors, you can use the cross product as normal vector:

n = PQ × QR = $\left[\begin{array}{ccc}i&j&k\\5&-9&0\\0&9&-4\end{array}\right]$ $\left[\begin{array}{ccc}i&j\\5&-9\\0&9\end{array}\right]$